Thermal Imaging Introduction

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5.1 - Temperature Measurement Overview Temperature measurement is likely the oldest form of Equipment Condition Monitoring. The first widely used mechanical mechanism with bearings was the war chariot of about 2,000BC. You can imagine the charioteer putting his hand on the wheel bearing after stopping to find out if it was working OK. Temperature measurement can be done very simply by use of your hand, by use of low cost hand held instruments, by permanently installed transducers or by more sophisticated techniques such as Thermal Imaging. Thermal Imaging or Thermography is a system where a visual image is created from the temperature variations on objects. Portable Thermal Imaging instruments enables rapid inspection of equipment with instant recognition of unusual temperature variations. This chapter gives you information to enable you to competently operate a Thermal Imaging Camera, be able to assess unusual temperature patterns observed in equipment and report on defects found. What is temperature and heat? For condition monitoring of equipment we are interested in temperature patterns and sources of heat and cold. The friction in a chariot wheel bearing generates heat and through the thermal conductivity of the bearing and the shaft, can be felt externally as temperature. Heat is a form of energy that is generated a microscopic level, eg friction between the molecules of substances. Heat energy flows throughs solids, liquids and gasses in three ways; • Radiation (direct contact of infrared radiation eg. heat from the sun) • Conduction (direct molecule to molecule energy transfer eg. bearing to hand) • Convection (general movement of gas or liquid eg hot air blowing onto you face) Temperature is the measure of movement or vibration energy of molecules, which is caused by heat energy. Click for more Temperature theory. Temperature on the outside of a bearing is a symptom of internal heat generation and its conduction to the bearing surface. It is also influenced by heat radiation and convection external to the bearing. How Can Temperature Be Measured? Temperature can be measured by contact or non-contact methods. The two most common contact temperature sensor are RTD’s (Resistance Temperature Detectors) and thermocouples. Both can give an electrical output relative to the temperature of the sensor. There are a number of hand held and permanently installed instruments systems using these sensors. Solid objects radiate infrared radiation relative to their surface temperature. Infrared radiation is similar to visible light but with a longer wavelength (see below). Infrared sensors are available that can measure the temperature from an object. Two frequency ranges are used, Short Wave SW & Long Wave LW. Thermal infrared cameras are detector and lens combinations that give a visual representation of infrared energy emitted by objects. Thermal cameras let you "see" radiated heat. Thermography cameras provide very detailed images of situations invisible to the naked eye Thermal energy is transmitted in the infrared wavelength, 1 to 100 microns. You can see from Figure 5.3 that infrared thermal energy is closely related to visible light. The human eye can only see the narrow middle band of visible light that encompasses all the colours of light in the rainbow. Thermal infrared cameras translates the energy transmitted in the infrared wavelength into data that can be processed into a visible light spectrum picture. Visible light is dependent on a light source (the sun or artificial) reflecting off an object to be received by our eyes. All objects above 0 degrees Kelvin (Absolute Zero) emit thermal infrared energy so thermal imagers can passively see all objects regardless of ambient light. The radiated thermal energy measured from an item can’t be exactly related to temperature without knowing its Emissivity, which is a surface characteristic. There are a number of other error sources, which will be discussed in section 7. Thermal cameras cannot see through walls, although you can gather some information about the inside of the wall as well as what is happening on the other side of the wall. For example you can’t see people inside a building from the outside of the building. You would be able to see and monitor the heat escaping from the building that would be a telltale sign of what is happening inside. You would also be able to get an indication of things like studs inside the walls, or damaged insulation in roofing or walls. You cannot hide from thermal imaging by covering yourself in mud to blend in like you may have seen at the movies. This might work momentarily, but infrared "heat" energy transfers well when objects are touching. Your body heat would quickly warm your camouflage, resulting in a thermal indication. This should dispel a few of the most common questions regarding infrared energy. Thermal imagers in Hollywood compared with real life are very different. These two pictures in Fig 5.5 show a defect in a junction box. One picture is visual & the other thermal. You can’t see inside the box but you can see there may be a problem. A heat defect inside a box must affect the surface temperature to be seen on a thermal image.

Temperature Conversions It is necessary that you are able to convert between Degrees Fahrenheit to Degrees Celsius and back. The Conversion are below. oF to oC – (oF – 32) x 5/9 = oC oC to oF – (oC x 9/5) + 32 = oF To convert differential temperatures oF to oC – oF x 5/9 = oC oC to oF – oC x 9/5 = oF Exerceses What is 100 oF in oC? What is 60 oF in oC? What is 80oC differential temperature in oF? What is 140oC in oF? How Is Heat Transferred? The left image in Fig 5.6 shows two adults and a child through an infrared thermal camera. After a minute of sitting on the couch the heat energy of the people is transferred and stored in the couch. The couch then gives off the heat when they get up (image on the right). This illustrates the fact that all objects radiate heat and shows the sensitivity of Thermal Imaging to detect the resulting temperature patterns. Understanding why a spot on an object has a particular temperature requires thinking about the three heat transfer methods, which are Conduction, Convection and Radiation. Conduction Conduction is the way that heat moves in a solid, by transferring thermal energy from molecule to molecule, heating up adjacent areas within the solid. Fig 5.6 shows an example. Heat flows from higher temperature locations to lower temperature locations to try to create temperature equilibrium. You may recognize this as the way a frying pan conducts heat from a hotplate to a piece of meat, or the way a coffee cup feels hot to touch if your hand is placed around it. Questions to ask • What is the physical construction of the measured object and the likely heat transmission paths? • What is the likely thermal conductivity of the components in the transmission path? • What are the observed temperature patterns? • What does this indicate about the likely sources and causes of the heat? Convection In convection, thermal energy uses a fluid medium to carry it and actually can induce a flow in the medium to move it more rapidly. Convection is used in air conditioning, moving air to cool a house. Consider free convection where a local fluid is heated and rises or is cooled & falls. This is normally external to an object but can be internal. Forced convection has a more substantial influence. Consider forced movement of fluids internal & external to equipment such as wind, cooling fluids and oil lubricant. Radiation Radiation moves with the speed of light and is observed in the way that heat transfers from glowing coals or from the sun to the earth. It is the primary way that your hands are warmed near a fireplace. Questions to ask - Is there a large heat source in the environment that could be radiating infrared energy? Outdoors the obvious source is the sun but other more local heat sources can also have a significant effect. Why Use Thermal Imaging? Temperature can be measured by relatively low cost instruments so what is the reason to use the more expensive Thermal Imaging Camera? • Portable contact temperature instruments are slow to use and dangerous or unusable in some application, such as for electrical or moving components. • With single point non-contact temperature measurement it is difficult to know exactly what you are measuring, where a thermal image gives an obvious and easy to interpret visual reference • Most temperature related defects are detected through differential temperature. Thermal Imaging can detect differentials as low as 0.1oC with easy identification of these differentials by visual analysis. • Thermal Imaging can inspect dangerous items (eg. high voltage electrical items) from a distance and inspect while equipment remains in service. • Thermal Imaging analysis is extremely efficient and allows inspection of a large amount of plant and equipment very fast. • Thermal imaging visual analysis allows scanning of large areas very quickly and typically identifies important problems unrelated to the inspection scope. 5.2 - Safe Thermal Imaging Data Acquisition Guidelines The Thermal Imaging Data Collection on Live Electrical Equipment The most important thing when collecting thermal images on electrical equipment is to assume all electrical circuits are live at all times. Some standard rules for live electrical equipment are, do not approach within: • 1 metre (stand-off distance) of low voltage equipment (> 100 Volts) • 2 metres (stand-off distance) of medium voltage equipment (> 1kV) • 6 metres (stand-off distance) of high voltage equipment (> 10kV)

The dangers from high voltage electrical equipment is show in the video chip “High Voltage Danger” in the disk with the book (Fig 5.9). It shows the potential hazards with high voltage equipment and the reason for a 6 metre standoff distance. High voltage equipment have been known to explode, so be extra wary with medium or high voltage components that show extremely high temperatures (Fig 5.10). Ideally the person doing the electrical data collection is a certified electrician or if not, to be under the instruction of a certified electrician. The relevant high and low voltage electric shock recovery kits are to be accessible whilst near live electrical equipment. Ideally the kits should be within 5 metres of the live electrical equipment. These items are to safely help remove people that have become attached to live electrical equipment. • Ensure you complete and comply with any electrical or other permits that are relevant to your work. • Before initiating data collection always carry out a location site inspection, taking note of hazards or items that may impact on the work to be carried out. o Never enter the vicinity of live electrical equipment where there is a spill or wetted area o The key hazard is falling into the live equipment, so be aware of anything that could make you slip or trip. Ensure you can’t be bumped by a person or by a moving object. Maintain good communication with other personnel in your area. • Ensure other personnel working in the area are aware of live electrical equipment and comply with stand off distance requirements. • When work is complete, ensure all panels and other items are closed and secure, the area around the electrical equipment is left clean & tidy and all permits are signed off. Switch board panels - Open only the switchboard panel under survey. Only the switchboard cabinets under survey should be kept open. Immediately after data collection close switchboard panel. Inform any other people in area of open panels. If there is difficulty with controlling personnel entry into the area, then use barricade tape or similar to secure area from entry. Electromagnetic Fields (EMF) – Higher voltage equipment with strong electromagnetic fields can generate voltages in nearby conducting items. Do not come in contact with equipment that may have an EMF induced step voltage such as metal power poles and switch yard fences. Other Hazards Including for Non-Electrical Thermal Imaging Collection Slips, Trips, Spills and Mobile Equipment – While using a Thermal Imaging camera your normal vision is reduced and you may be distracted so that you do not notice local hazards. Some rules to be followed: • Assess all local hazards before using the thermal camera o Especially the possibility of mobile equipment such as fork lifts entering your area o Review your proximity to moving or potentially moving equipment o Review your proximity to high temperature components o Review your proximity to fluids that could splash or leak and especially if those fluids are high temperature • If the location you are to work in has an operator control room or a key operator, let them know you are on-site. Ask about local hazards and about problems with equipment to be monitored. • Ensure safe footing at all times o Review uneven surfaces o Wet or slippery surfaces • Never operate camera whilst walking Fire, smoke, Explosion, Major Leaks or Gas – Ensure that on entry to enclosed area such as switch rooms etc, you assess available emergency evacuation route. This is in case of fire or smoke or other emergency occurs. Job Safety Analysis (JSA) – If there is any special hazards associated with the data collection then a formal written Job Safety Analysis is recommended (or equivalent system). If the data collection requires working within the recommended standoff distances then a written JSA or equivalent would be mandatory. An option where the risk of contact with live electrical equipment is higher is to wear electrical insulating gloves, as the hand is the most likely part of the body to contact with a conductor. If working in a confined space where other parts of the body may come in contact with conductors, then electrically insulated barriers or clothing could be used.

5.3 - Thermal Imaging Measurement Use of a Thermal Imaging Camera – The easiest way to learn how to use a thermal imaging camera is to get instruction from an experienced user. It will typically only take 30 minutes instruction to learn the initial basics of use. If this is not available then you need to read the camera operating manual. The manual should also be used to learn the finer points of camera function and how to adjust these settings. Basic of operation should include: • Turning on and off • Checking that a standard setup is being used including overall temperature range (you should have a standard setup checksheet) • Focusing • Zooming in and out • Adjusting the displayed maximum and minimum temperatures • Stilling the live image • Storing images Use of a Digital Camera - For every thermal image that is recorded for a report, there should be a standard digital photo that can be used as a reference. An example is given in Fig 5.13. The reasons for this are discussed below:- • It assists with recognition of items within the thermal image to assist with diagnosis • It assists with the identification of emissivity & other error sources • It enables better understanding of component to assist diagnosis • Assists with the identification of the components location by others and by the repairer. Preparation and using a checklist before going to site - Ensure you understand the type of report required and if there is a previous report, get a copy. Written details of the work scope is desirable. • Turn Thermal Camera on and view a thermal image to ensure it is operational • Check the battery is fully charged & spare battery is OK, if one is required • If your workscope is large ensure you have a spare memory card or take computer to site Required Items Checklist • Belt mounted pouch to store items • Note book and 2 pens & Digital camera • Small Torch (focusing type best) • Check-sheet of items to be inspected Optional Items Checklist • Black Felt tip parking pen and black tape (to assist with temperature checking) • Multi tool pocket knife (eg. Leatherman) • Scraper and rags • Information tags for identifying the location of defects • Extra PPE such as Gloves and Goggles Use of the Thermal Camera On-site 1 - Overall scan of an area - Whatever the scope of a thermal imaging job, at each location you visit, do a quick overall scan of the whole area. Record any temperature pattern that appears unusual or may be of significant interest to others. This does not necessarily have to be done when you arrive in an area and can often be done during minor waiting time or during the inspection work or when you are in a better location to do an overall scan. This process can significantly add to the value of the inspection, as important defects are often identified this way. If no defects are found, the time involved at each area should be less than 20 seconds. If you can’t interpret the temperature patterns identified or what the equipment involved is, ask for the assistance of someone who knows the equipment better. If you are not sure if the temperature pattern represents a real problem, the images can be added as ‘items of interest’ at the end of your report. 2 – Inspection preparation - Record relevant background data such as date, time of day, ambient temperature, humidity, wind speed and other atmospheric conditions such as dust or mist. Some cameras have a voice recording function to record information but you should also have a notebook to record site issues. For each item on the inspection scope, measurement preparation involves identifying its operational status, doing relevant 5 senses inspections, identifying hazards and organising any inspection preparation (eg. getting the electrical panel door opened). Information about operational/current loading is often very useful. A review of product throughput by observation or from discussions with operators will also give an indication of equipment loading. Many motor control panels have current meters and motors have full load current rating on their nameplates, which is useful to record. If the inspection scope does not identify equipment names and associated item codes, these should be recorded. If there is any uncertainty about the equipment naming, which often occurs, ensure that the visual digital photo taken has enough background references to make identification obvious. If the distance from the thermal camera to the object being measured is greater than 2 meters, the distance should be recorded and included in your report. 3 - Identification of items of interest within the inspection scope –First adjust the viewed thermal image if required to get a clear picture (see details for Specific camera). The most important issues with a thermal image are that it is in focus and the appropriate overall temperature range is selected. Other adjustments that may be required is the viewing angle, viewing distance and emissivity. Identify temperature and temperature differentials of interest. Look for components or locations of interest with unusual temperature patterns or high temperatures. Determine the maximum temperature for the components of interest. Include the assessment of location emissivity and other possible temperature errors sources (see section 5.7). In most monitoring situations the temperature accuracy only needs to be good enough to determine the defect severity category. Determine if there is an identical or similar component that may have similar loading with a lower temperature. Measure the temperature of this reference component at the location of the maximum temperature on the component of interest. Determine the differential temperature & assess severity. If there is no logical reference component then the reference temperature should be taken as the background temperature for the component location or the ambient temperature. 4 – Assessing Defect Severity - Temperature differential severity standards (This is an rough indication only) • 0 to 10o C :- OK. Item may be of interest but probably will not require any action • 10 to 20o C :- MODERATE. Item of interest and may require some preventive action • 20 to 40o C :- WARNING. Corrective action required but may not be urgent • 40 to 70o C :- SEVERE. Corrective action required urgently • 70o C and above :- SEVERE. Corrective action required immediately (take action now!) These standards can be used for both mechanical and electrical but actual mechanical defects severities will differ from these standards far more often. Electrical severities can be modified depending on the size of the components. For example heavy bolted connections can withstand higher temperatures than smaller wire connections. If you are not sure of a particular severity, discuss with others. 5 – Recording of data – The ideal is to find a significant defect and fix it immediately, if it is a simple task. This is not practical for most circumstances as isolations are often required or the plant may not be easy to shut down. No action may be worthwhile on moderate defects but you may need a record the image to check it later, to ensure it has not deteriorated. It is not usually practical to depend on memory so either the thermal images has to be digitally saved for later review or a report of the defects needs to be produced. Exception Reporting - The recommended thermal imaging reporting method is Exception Reporting. This is where only information on defects found, of ‘Moderate’ severity and above is recorded. The thermal images recorded focus on the specific component defects. Baseline Reporting – This can be used on the initial monitoring on a regular job or where the equipment is very critical and a full temperature history is required. Thermal Images are taken of all items in the scope. This style of reporting is more time consuming and is typically only used in special situations. Exception Reporting Plus Monitoring of temperatures - This is normal exception reporting plus recording of maximum temperature on a predefined list of components. This can be used where there is an advantage in having a trending history eg. bearing and motors. The temperatures are usually recoded onto a pre-printed check-sheet. An option is recording on synthetic paper and trending on site. Data to be recorded with Thermal Images – When saving the selected thermal image there is other data that should be recorded. Record in notebook or voice recoding further relevant details such as spot emissivity, object distance, operating condition, current loading and any variation to background conditions. Also record selected defect severity, the defect description and possible cause. When taking the associated digital photo, ensure there is enough background detail so that the component involved can be differentiated from similar components. This protects against possible confusion in equipment naming. Emissivity & Reflectance The temperature a Thermal Imaging camera measures is affected by an objects surface characteristic. Very shiny objects can produce very large errors (See Fig 5.17). The most important temperature surface effect is Emissivity (E). This parameter gives an indication of the temperature error when making non-contact temperature measurements. A surface that maximises the amount of surface heat radiation that can be measured is called a Black Body. Emissivity is a ratio of the non-contact measured temperature divided by the contact measured temperature. There are no perfect black bodies but generally mat black surfaces come close. A tables of Emissivity for Metals & Non-Metals in included in the disk. Most normal objects are in the range of 0.1 to 0.95. Mirror surfaces can be below 0.1. Oil based paints regardless of the visible colour have an emissivity of around 0.9. Thermal cameras have a emissivity setting that can be adjusted. Shiny surfaces have another characteristic that can create significant errors in measured temperatures. This is Reflection. Heat reflects just the same as light does on a shiny surface. As most objects reflect some heat, cold or hot items in the environment can cause a significantly effect. These items and other causes of errors will be discussed further in Section 5.6. Analysis of Thermal Images The most important measurement to obtain while collecting data on-site is the maximum temperature of a defect. The next most important is to capture an image that best shows the temperature profile on the object. In some situations the thermal camera may have to be on different overall temperature range setting to achieve both. This requires you either record two images or manually record the maximum temperature and then record the best temperature profile image. Most fine-tuning of a thermal image for a report can be done back in the office with the report writing software (post-processing). There are three camera settings that can’t be adjusted for in post-processing. They are:- • Camera Focus • Overall Temperature Range • Distance and Angle to Object Errors in any one of the above may result in improper temperature or temperature difference measurements. This is discussed in more detail in Section 5.6. Understanding Temperature Patterns In a stable environment all temperatures equalise. There has to be a heat source to cause a temperature profile (variation along a line). If there is no heat source inside an item then to measure a temperature differential the heat must be supplied externally. Eg. from the sun. The thermal equilibrium of the object you are measuring has to be upset to see a temperature pattern. If you were trying to measure the level of a tank (Fig 5.19) but the tank was in a temperature controlled room, you would not see an external pattern if the tank liquid and walls had reached thermal equilibrium. Heating from the sun or the normal variation in daily temperature is often enough to upset equilibrium and create temperature patterns. If your monitoring is relying on this effect, then you should always consider if the temperatures is in equilibrium, if you get a negative result eg tank shows no thermal level indication. Where the object being measured has an internal source of heat or cold then monitoring is easier. If the heat source in a object is small, it is often better to measure before sunrise or after sunset to eliminate the effect of the sun. Thermal Imaging Measuring Techniques Both thermal cameras and the reporting software have a number of tools to assist with quantifying and recording of temperatures. A Cross Hair Spot can be located anywhere on a thermal image and have the temperature automatically measured. A Spot is often used for the reference temperature, as the spot can be located on equivalent location high temperature location on the reference component. Area temperatures is the most widely used tool. A Box (or circle) is created and the maximum temperature within the box is automatically measured. The example in Fig 5.20 shows a Spot within a box (SP01). The spot temperature was 92.1oC and the Box temperature (AR01) was 92.9oC. This shows the advantage of using the Box tool over the Spot tool for finding the Maximum Temperature. How temperature varies over a component can be extremely important for a defect diagnosis. Line temperature profiles are a powerful tool to display this. An example is given in Fig 5.21 of the temperature profile across a gear. This can give a graphic indication of gear tooth loading and lubrication variations. Differential temperatures can be automatically calculated from measured values in reporting software. This is very useful for automatically calculating the differential temperature between the reference component and maximum component temperature. 5.4 Electrical Thermal Defect Pattern Interpretation Learning interpretation of Thermal Imaging defect patterns is best done through examples. This section includes a large number of electrical equipment thermal images with some explanations were required. Electrical Hot Joint Failure Figure 5.23 - These are the four most common electrical defects Poor Electrical Cable Connections / Hot Joints The most common electrical fault is poor cable or wire connection, causing a high resistance joint that creates heat with current flow (Hot Joint).

The defect in Figure 5.26 shows a poor bolted cable connection with a large localised temperature increase. Note some heat conduction into surrounding areas. Three phase electrical equipment give readily available reference components to calculate differential temperatures as shown in Fig 5.26. Large bolted cable connections are more resistant to failure, as indicated by the large differential temperature.

Broken Wire Spiral heating can often be seen in multi-stranded conductors. Due to strand breakage or corrosion or a poor connection, the hot strand is carrying more load than it should. The problem will only get worse, eventually resulting in this strand melting and shifting the defect to another strand. Uneven spiral wound insulation can also show a similar effect on overloaded cables.

More Hot Joints Both left and centre phases of Fig 5.32 fuse switch are showing abnormal heating. It is probable that three separate defects exist at both fuse clips and in the switch of the left phase. The fuse clip on the left phases was approximately 18 degrees C warmer than on the right phase. In situations like this with multiple defects, it is also important to take your time to carefully examine the component from several different angles in order to have enough information to diagnose the situation. The connection on Fig 5.33 starter is approximately 30oC warmer than the T1 connection. When measuring temperatures it is critical to also know the load, since temperatures at this abnormally high resistance connection will increase at the square of the load. The "A" phase line side of this switch is showing a classic high resistance pattern typically associated with a loose or corroded connection in the lug. The actual connection is obscured by the breaker, which is also starting to heat up due to radiation and conduction from the hot connection. Is the structure in front of the switch (the large black rectangle with several holes in it) actually that cold? It is doubtful. The material is probably simply reflecting the cooler background temperature because it is a very poor emitter (low emissivity). In Fig 5.35 the connection on the block measured 110oC, more than 55oC over the reference. Extreme care should be used when inspecting components this hot, as damage may have taken place, leaving an unstable condition with risk of an electrical explosion, especially with high voltages systems The "C" phase fuse circuit in Fig 5.36 is hotter than the other two. It appears to be a connection problem at the top of the fuse, but a second defect may be developing at the bottom of the fuse as well. In this case, when doing outdoor surveys, you should take into account the load of the system, the wind conditions, and ambient air temperatures. For example, a 20 kph wind can cut the temperature of the hot component in half, while having little effect on the reference connections.

Fig 5.42 - Fuses clips are vulnerable to failure because they depend on spring tension for their electrical integrity. Even heating a clip to as little as 93°C for a month causes it to lose that spring tension, resulting in a trend toward rapid failure. Note the fuse cap, because it is reflective, appears much cooler than it really is.

Circuit Breakers and Contactors Fig 5.46 - The "B" phase of this breaker appears to have a poor connection. It can be diagnosed as a connection pattern because as you move away from the connection, which is the hottest point (partially obscured by the breaker), the heat dissipates. Further away from the point of high resistance the conductor is the same approximate temperature as the other two phases. Fig 5.47 - The load-side centre phase connection of this primary feed pump breaker is running approximately 12 degrees C over the left phase. Condition of the right phase is unknown, but further investigation is warranted. Fig 5.48 hot bus connection to the back of the breaker represents an extremely serious defect. The heat appears to be generated inside the breaker. This means the temperature we see is greatly diminished by comparison to the actual point of contact that is inside the breaker. Lastly, the material we are looking at has a very low emissivity, so if it looks at all warm or hot, it is extremely hot! This type of defect should generally be checked and repaired immediately or if this is not possible, monitored very closely.

Fig 5.49 panel circuit breaker is hot! Is it a problem? Without a load reading, diagnosis is difficult. This may be the only energized breaker in the entire panel.

The right phase of Fig 5.50 moulded case breaker shows a classic pattern associated with a loose connection. Note how the temperature diminishes further away from the source of the heating, the connection. While loading conditions should be taken into account, this is more than imbalanced load.

Fig 5.51 The entire nearest row of tubes is cooler than the normally operating tubes behind. It is clear that the oil is not being properly circulated. The life of the oil in a transformer is cut in half for every 10 degrees C beyond 60 degrees C. The life of the transformer itself can also be affected by temperature. While you are checking the cooling tubes, also check to make sure any associated fans or pumps are working well. Fig 5.52 image shows normally operating cooling fins on a transformer. Look for even temperature gradations. If you see a cool tube or bank of tubes you can assume there is no fluid circulation, which is probably caused by a plug or an airlock. Temperature increase can be caused by either increased load or decreased cooling capacity.

Transformer Connections Fig 5.54 - Heat is being generated at the connection point inside the transformer and out to the base of the bushing. This typically represents a severe defect requiring immediate shutdown, monitoring, or other supplementary testing to determine the exact extent of the problem.

Fig 5.55 - Often it is not possible to be in the ideal position for monitoring. By shooting this bushing in an inaccessible, fenced, substation, the thermographer was able to alert the substation operators that they had problems in this transformer regulator.

Transformer Connections Fig 5.56 & 5.57 - On this pole transformer a secondary bushing was found to be hot. But you've got to look closely at the pattern to notice the hottest spot is not where the bolted connection is, but it is coming from the internal conductor. When you see a pattern such as this, even small differential temperatures can mean BIG trouble internally!

Fig 5.58 - The bottom photo shows what can happen to these internal connections when only a small temperature difference exists. When this one was found, it showed a 5.5-degree C temperature rise. After taking it out of service, you can see the actual temperature difference was substantial.

Inductive Heating Fig 5.60 shows an incorrectly wired automatic power factor correction cabinet. What is shown is high current induction heating in the cabinet structure. Circuit Board Faults This integrated circuit board on in Fig 5.61 was in an idling state when inspected. Yet as you can see, there is a bad fuse connection.

When You Don’t Know What an Equipment Item Is You can still make sensible comments in most circumstances. When there are three of an item together it is generally a three phase system. Try to confirm that the supply and output cables are grouped together to increase the certainty of this assumption. As seen below, if the item is a three phase system then the 80.4oF (45oC) between the centre and lower phases, which is serious. If not three phase, the maximum temperature of 167.9oF (75oC) is still worthy of a comment.

Normal Temperatures Even though several things in Fig 5.63 appear pretty warm, this image does not show any real problems. It is, in fact, a typical "good" pattern found in many motor control centres (MCC's). The conductors and their connections are all evenly warm, as they should be. The starter coil is quite warm, which is normal when it is energized. There are some people who say they can perform effective electrical surveys and NOT open up the panel doors. They are WRONG! All Fig 5.64 thermal image shows is that one panel is warmer than the others either side. It does not show that there is an electrical problem inside the cabinet. This may be the only energized panel in the entire group, a perfectly normal situation. Or there could be a starter coil operating normally right behind the upper right side of the door. It could also indicate a potentially serious defect. These overload heaters in Fig 5.65 are from Fig 5.63 & are hot, as they are supposed to be when energized. If one or more were sized improperly, the thermal image would show it. Even though they are made of a shiny metal, the overloads appear warm because of a situation called "cavity radiator effect". Similar nearby surfaces are equally warm, but appear cold due to their low emissivity.

Component Damage Warning Levels Most Thermal Imaging assessment is done through analysis of the temperature difference between similar components. An indication of defect severity can also be made from its temperature difference from ambient. An indication of differential temperatures from ambient above which serious damage may start to occur is given below (This is only a general indication) • Conductors 50oC • Connectors and terminations 50oC • Circuit breakers - moulded case 20oC • Circuit breakers other and switches 30oC • Coils and relays 60oC • Motor casings 70oC • Dry Transformers 70oC • Oil Cooled Transformers 60oC • Oil Transformers (differential top to bottom) 10oC 5.5 Mechanical Thermal Defect Pattern Interpretation The following mechanical components are typically inspected by thermal imaging. • Rotating Equipment Bearings • Rotating Equipment Casings • Process Applications • Ovens & all heated systems • Pipework inspections • Couplings • Steam Traps • Valves • Roofs • Refrigeration & Coolers

Bearings Thermal Image of the bearing in Fig 5.67 indicated excessive localised temperature. The cause was friction from a seal that had failed.

Gearboxes Misalignment of the motor to the gearbox in Fig 5.69 caused high thrust loads and caused higher input shaft bearing temperatures.

Fig 5.69 shows a gearbox bearing indicating abnormal bearing temperature. Inspection of bearing indicated that the bearing was incorrectly installed.

Fans The fan in Fig 5.70 is an overhung impellor design. The hot bearing is on the impellor side bearing. Note the bearing housing temperature is similar except where heat is being conducted into the base. Unbalance or excess grease could produce this even temperature pattern.

The Fan in Fig 5.71 blows air into the cooler chamber of the cement plant. The left bearing on the shaft shows an abnormal heat pattern, approximately 10°C higher than the right bearing, which is running at a normal specification temperature. This is a Moderate severity defect needing investigation. A bearing problem, excessive V belt tension or axial forces could be causing the temperature defect.

Belt Drive Defect Slipping in the drive belt shown in Fig 5.72 creates significant friction and temperature between the belt and the pullies. The identical pullies opposite make a dramatic comparison.

Shaft Misalignment The thermal images Figures 5.73 to 5.75 show a trial carried out with three levels of misalignment, with increasing severity of temperature patterns. The motor bearing got hottest, as motor bearings tend to be smaller and less able to take extra load.

The pump shown in Fig 5.76 has a higher temperature on the bearings each side of the coupling. This is typical of misalignment.

Both motors in Fig 5.77 are loaded similarly. The one on the right of the image is running at 60oC, 22oC warmer than the motor on the left. In this particular case, the root cause of the overheating was traced to misalignment. You can see the advantage of having a close-by temperature reference component.

Fig 5.78 is from a food plant and shows a Food Mixing Mill above and is driven from below. It has a misalignment defect and possibly a bearing defect. The mill is used to mix several ingredients to make a spicy food sauce. In this lower speed application the highest temperatures are on the rotating shaft areas closest to the bearings. This is due to the large bulk of the housings absorbing the bearing heat. Note the maximum on the temperature scale is only 42oC so the temperature differences are not large. This does not mean it is not a severe fault as lower speeds defects produce lower levels of heat.

Problems with Larger Gearing A widely used condition monitoring method for large open gearing is analysis for gear misalignment and lubrication defects by thermal imaging. Areas of the gear tooth surface that are more highly loaded or poorly lubricated will show up as a higher temperature. Fig 5.79 shows a grease lubricated open gear from a mining application. One of the gear teeth has a temperature profile drawn by the thermal imaging software. This shows a higher temperature on one side of the gear, which is a symptom of gear misalignment and will cause a serious wear problem if not addressed. Fig 5.80 shows a severely misaligned open helical gear. The temperature variation is 57-75oC (18oC) along the angle of contact from pitch line. This technique is also relevant for normal gearboxes, if they can be stoped & a cover removed. Conveyors

Mobile Equipment Use of thermal imaging for mobile equipment has the advantage that the equipment does not necessarily have to stop operation to do an inspection (Or at worst only has to stop for a short time). Fig 5.85 shows a large dozer in operation. Both the hydraulic cylinders at the front & the final drive show higher temperatures. Defects such as bypassing of cylinders can be easily observed. With very large mobile equipment such as overhead cranes, draglines (Fig 5.86) and shoves it is possible to do thermal imaging inspection whilst on the equipment. This would usually require special attachment points to be installed so that safety harnesses can be used.

Mechanical Stationary Equipment High Temperature Equipment Fig 5.87 shows a torpedo ladle that carried liquid iron. If the refractories inside the steel shell fail massive equipment and rail damage occurs, as well as being a huge safety risk. Thermal imaging is a well-recognised method of monitoring these ladles.

Fig 5.89 shows a thermal image of an area of furnace wall insulation or refractories. The high temperature area indicates insulation or refractory breakdown, inadequate installation of insulation or refractories or inadequate design.

Fig 5.90 shows a boiler with an area of poor insulation. This type of defect can be both an energy efficiency and a safety issue.

Cement Kiln - Fig 5.91 shows high temperature ductwork located at a cement plant where air is blown in to cool the clinker material. The side wall of the kiln has several bad areas of refractory breakdown. You can also see that there is some correlating paint discoloration in the visual image.

The abnormally warm areas on the boiler in Fig 5.92 has surface temperatures in excess of 132 degrees C and are caused by a deterioration of the refractory. It is important to know the structure of the unit, its internal temperature, and variations in thickness and type of refractory to determine risk of failure. It is possible to calculate the thickness of the remaining refractory by using internal and external temperatures.

The abnormally warm area around the door in the furnace in Fig 5.93 indicates a pattern of excessive air leakage. Monitoring this condition over time will help predict the rate of deterioration.

The refractory lining in the stack has cracked and been damaged, allowing excessive conduction of heat energy. Such thermal stresses will often lead to rapid degradation of insulating brick in the vicinity of the crack.

Pipework Inspections Pipework where the fluid temperature is slightly higher than ambient can show internal sediment build-up as shown in Fig 5.95. An external heat source such as sunlight on the pipework area of interest can achieve the same effect. Fig 5.96 shows the area above a buried steam pipe. The pipe was not very well insulated. Fig 5.97 shows a large diameter wooden stave pipeline (Tasmanian Hydro Scheme). Higher moisture levels in area of wood rot are cooler than other areas, which are heated by the sum. The same mechanism can be used to locate leaking underground water pipes. Steam Traps

Fig 5.98 shows three steam traps. The two on the right are working normally with cooler discharge lines at the top. The trap on the left is leaking steam, giving a high temperature on the discharge line. This will be cause a very large loss of steam, which is a major energy efficiency issue.

Fig 5.99 shows the same issue with the thermal image on the left having a hot discharge line compared to the one on the right. Fig 5.100 shows the opposite issue with the image on the left being completely blocked. Wet Insulation in Roofs Thermal imaging roof inspections are usually trying to find leaks. In the daytime the sun heats the roof structure. After the sun sets the roof begins to cool. If there is a leak in the roof membrane the insulation inside the roof will become wet. The wet insulation has a higher thermal mass than the rest of the "dry" roof structure. The "wet" areas will maintain heat energy longer than other areas. Fig 5.101 shows a clear picture of the damaged area. The temperature difference is very small (2oC).

Tanks Many tanks have no integral level measurement system and so thermal imaging gives an easy method to check levels. The technique relies on there being a temperature difference between the tank liquid and ambient. Fig 5.104 also shows that sediment is building up in the bottom of the tank. Note the lower sediment level at the discharge valve. In Fig 5.105 the tank liquid is warmer that ambient. In Fig 5.16 the tank liquid is at around average daily ambient but the heat from the sun is enough to heat up the tank shell where the fluid is not in contact.

Process Monitoring Thermal Fault Patterns There are many applications for thermal imaging in manufacturing and process monitoring. Fig 5.107 and 5.108 show two applications.

5.6 Error Sources and Their Effects

Thermal imaging is a very easy technique to use but there are a number of ways that you can be confused and make the wrong diagnosis. The main issues are listed blow. This sections shows how they can be avoided. • Surface emissivity (ISO std)( comparison on different surfaces) • Reflection and Transmission (ISO reflected) • Atmospheric issues • Effect of the sun • Heat conduction or convection or radiation from a nearby source • Cooling air flows • Object shape and surface • Electrical currents effecting camera • Resolution • Range and span • Image focus • instrument settings • Instrument accuracy Understanding these issues enables you to be able to identify, and correct or reject bad data. Error Sources from Surface Emissivity The effect of emissivity (E) has already been discussed as a measure of the effectiveness of a surface in radiation of its heat (Section 5.3). The can of beer in Fig 5.110 is ice cold straight out of the fridge. When scanned with an infrared camera you would expect the entire image to be relatively even in temperature and to appear "cold" in relation to the background. The paint on the outside of the can has been scratched off in a small area. The bare aluminium has a much lower emissivity than the painted aluminium. The camera can only allow for one emissivity setting at one time, so the area of bare aluminium appears hotter than the rest of the can. Examples like this one show how emissivity can cause false temperature patterns in the field. If you look closely the left side of the scratch appears hotter than the right side and this aligns with a slight vertical heat reflection pattern on the can. Cylindrical shapes will have vertical reflection patterns. As you can see the writing on the can in the thermal image, it means that the writing has a slightly different emissivity to the rest of the can.

It is hard to determine the emissivity of all objects in your field of view. It is also difficult to determine the emissivity of a single known material. The surface of an object (especially metals) changes with the passing of time. For example, corroded copper (E-0.78) has a significantly different emissivity value than shiny copper (E 0.02). This difference introduces a judgement call on the part of the thermographer. How do you determine how corroded or shiny a piece of copper is? The answer is you can come close but you cannot be exact. Additionally, the numbers in the emissivity table are approximates or averages, in the real world values may be slightly different. So how do we manage emissivity? It is possible to determine actual emissivity values for a material but it usually is not practical. In most thermal imaging applications exact temperature measurement is not necessary. Most thermal infrared applications rely on temperature difference (Delta T) rather than exact temperature readings. There will often be more than one component next to each other. If you use the same E value for the same locations on both components they will both differ by the same amount. If one component was reading a normal 40°C and the adjacent component reads 65°C we are left with a Delta T of 25°C. This would indicate a defect and as you can see, negates the emissivity problem. E values become even less of a problem when trending temperature over time. If the same component with the reading of 40°C has a reading of 45°C the next time, then 50°C the time after, we know a defect is developing. This is regardless of the error introduced by emissivity. When temperatures get very high surface corrosion may occur, so look for changes in the digital photo over previous photos if you suspect this. The important thing to remember is that exact temperature measurements are difficult to obtain (do not promise this to people unless you can find the exact emissivity). Temperature difference (Delta T) is more important than exact readings in most applications and that trending a spot on a component can reveal defects regardless of E value error. In the real world you pick an emissivity value that approximates the area you are imaging and then you record it and maintain that same setting every time you scan that object. Error Sources from Thermal Reflection The same as light is reflected by a mirror, heat also reflects from shiny surfaces. Fig 5.111 shows a low level temperature source from a human body but it still has enough heat to reflect off the pipe behind. The image in Fig 5.112 is a probable loose connection. Note the almost perfect "mirror image" of all three phases in the highly reflective structure above the conductors (at the very top of Fig 5.112). The lower the emissivity of an object, the more likely it is to reflect background heat or cold. As there are no perfect black bodies (emissivity of 1) always inspect the local environment for hot or cold sources. Moving the camera location can easily prove a reflection. A reflected heat pattern will move. Error Sources from Atmospheric/Distance Issues Certain constituents of the atmosphere absorb infrared radiation. The most important gasses are Water Vapour (H2O) and Carbon Dioxide (CO2). For the above reason higher humidity, mist, rain or fog will have an effect on the accuracy of temperature measurements over distance. The graph in Fig 5.113 shows the Correction Factors for a Long Wave camera with distance, for a standard atmosphere. A Standard atmosphere is 15oC, 1 atm pressure, 50% humidity and visibility to 10km. The use of special filters can have a negative effect on distance correction factors. In some situations, such as with high temperature gas in a burner, the atmosphere itself can be a source of thermal radiation and can significantly effect temperature measurements. Error Sources - Effect of the Sun The sun is a massive source of heat. Radiated heat from the sun can have a significant effect on the surface temperature of objects. It is also a strong source of reflected heat. Moving the camera location will readily determine if reflection is the source of a temperature pattern. Any outside daytime monitoring requires care that effects from the sun are not recorded as defects. Except possibly at midday most object will have a shaded and a non-shaded side, which will have a temperature difference. If there are reflective objects in a location the temperature of some objects or locations could be further increased. One of the connections on the pole mounted transformer in Fig 5.114 appears to be hot. If you suspect this might be a reflection of the sun, simply move your viewing location slightly. If the hot spots do not move (and it did not!), then it is not a reflection. Although it is not extremely hot at this time, failure may well be imminent due to the small size of the connection. Error Sources from Cooling Air Flows Cooling airflows will have a significant influence on a surfaces temperature. See the chart in Fig 5.116 that gives a correction factor for wind speed. Air can flow at different speed at different location on an object, which will create temperature patterns. Determine what part of an object will be most shielded from the air movement and if that explains the temperature pattern. Never forget that a hot object can create its own airflow by convections. Note cooler streak up the pipe in Fig 5.115. Upward convection airflow from the heat in the pipe is deflected away from this area due to the pipe below. The vertical flow is called a chimney effect. An object can also be heated by airflows if there is a hot object below the item. Airflow cooling does not create a measurement error but it can create an error in severity assessment. Ask yourself what would the temperature and patterns be without the airflow or wind. Errors - Heat Conduction from a Nearby Source In the paragraphs above the effect of convection of heat from a nearby source was discussed. Heat Conduction from a nearby source has to be considered as well. The images below in Fig 5.117 shows the difficulty in assessing a hot outboard bearing on a motor when the body of the motor (and potentially the motor shaft) is also very hot. What is required is to confirm that the temperature profile from the bearing area to the motor body and the bearing area to the motor shaft show reducing temperatures. That is, the bearing area is hotter and thus is a source of heat. Determining severity is harder if there are other significant sources of heat. Error Sources from an Object Shape and Surface If an object surface is viewed from an oblique angle (more than 60o angle from a direct on view) then it may appear cooler than it is. An indication of this effect is given if the edges of the surface are cooler or warmer than expected. If the surface is rough it may reduce this effect, as a percentage of the surface will be less oblique to the camera because of the roughness. Changing the position of the camera to change the angle to the surface can easily compensate for the effect. Other surface effects come from surface build-ups such as flaky rust that can act as an insulator. Radiant thermal energy does go through glass or Perspex. Even though you can see components through visually transparent surfaces, you will only measure the transparent glass or Perspex surface temperature. Fig 5.118 shows a window material that will transmit radiant thermal energy but they are expensive. These are some times fitted to electrical cabinets that can’t be opened while in service. Short Wave and Long Wave Cameras There are two types of thermal camera technologies that work on different thermal radiation wavelengths. They are Short Wave & Long Wave. See Fig 5.119 below. The long wave is the more common type. Each has its own advantages. Short Wave Camera Advantages • Can look through flames to measure a burner temperature • Can measure the temperature of a transparent plastic film • Better for higher temperature applications • Less atmospheric losses Long Wave Camera Advantages • Less affected by other atmospheric issues • Less affected by reflections from sun • Better for outdoor applications Error - Electrical Currents Affecting Camera Very high electrical currents (high electrical or magnetic fields) can affect camera displays. It is also possible that the camera itself could be affected but this is less likely. To test these effects move the camera away from the source of the electrical currents such as large electrical cables or motors. An option is to record a thermal image and move away from the current source to view the image. If it is not possible to avoid this effect then some cameras are available with removable screens that can be attached with an extension cable or external monitors can be attached. Error Sources from Resolution Resolution is the performance of a thermal camera in measuring small or distant temperature sources. If a thermal imaging camera is too far away from an object then the size of smallest pixel of temperature becomes bigger than the spot of highest temperature. When this happens the camera pixel is also measuring the lower temperatures around the high temperature spot and so the measured temperature is reduced. The options are to try to get closer or if this is not practical to take into account of the error in the severity assessment The factors involved in resolution are: • Distance of the camera to the object • Field of view (FOV) angle, which is the magnification of the camera lens used. Various lenses may be a available for a camera. • Pixel or focal plane density of the thermal detector (typically 320x240 pixels) • Defect size - The area of object maximum temperature facing the camera Error Sources from Instrument Settings Range and Span - A thermal imaging camera may be able to measure between -20oC to 1200oC but it can’t do this on the one thermal image. Set ranges are used. These are typically: • -20 to 40oC • 0 to 100oC • 80 to 400oC • 350 to 1200oC Within these ranges the actual temperature span (max & min) of the image can be adjusted on-site or in post-processing. If the incorrect range is selected, this can’t be adjusted for in post-processing. Measurement of maximum temperature may require a different range to the best range for the display of the objects temperature pattern. As previously mentioned either record two images or manually record the maximum temperature. Image Focus - As with range, the camera Focus can’t be adjusted in post-processing and so must be correct before the image is stored. Error - Thermal Camera Accuracy and Calibration The measurement accuracy in an ideal situation (emissivity of 1 and no atmospheric effects) is typically 1oC up to 100oC and 1% of the actual temperature above 100oC. This means the a measured temperature of 85oC could actually be 84oC or 86oC using a contact thermometer. For normal monitoring applications where patterns are often more important than absolute temperature measurement, this level of accuracy is acceptable. Errors from emissivity and thermal reflection are usually much more significant. The calibration of a thermal camera can be easily checked. The temperature of a known near black body is measured by a contact thermometer and compared to the camera measurement. The other approach is to use known fixed temperatures such as boiling water and ice water. Error Sources from Heat Source Variation As previously discussed all thermal patterns require a heat source or heat flow to prevent thermal equilibrium. Heat sources can vary significantly over time. • The current and thus heat in an electrical system will vary with system load. • Heat generation in mechanical systems can vary with the quantity of lubricant used • Cooling systems can vary in effectiveness • External heat sources such as the sun will vary in intensity The risk is the severity assessment may not be correct if an increase in the heat energy occurs after measurement. You should try to understand possible heat source variation cycles and try to take them into account when making judgements. Be able to identify and correct or reject bad data The error sources discussed have a number of Corrective Actions:- • Changing camera settings o Emissivity, Range, focus o Have emissivity data available • Object surface preparation o Clean off flaky rust and dirt o Tape or paint on shiny surface to improve emissivity (where safety allows) • Changing measurement position o Look for possible reflections in the image & see the effect of angle an change • Changing time of day for collection o Before dawn and after sunset is best • Shield object from heat or cold reflective sources o Placing your body or a sheet of cardboard to block heat or cold source • Estimate the effect of various errors on the maximum temperature measured o Wind or convection air flows o Equipment load or other heat source variability o Camera resolution and distance to object o Atmospheric effects 5.7 Fitting & Using Camera Accessories & Attachments • Batteries and their care • Filters and lenses • External screen • Video and Audio Batteries for Thermal Cameras Proper battery care is the most important part of maintaining a Thermal Camera. The most important issues is to ensure batteries are fully charged before use. You may need spare batteries if you are to use the camera heavily. Some cameras are heavier on batteries than others. Changing battery packs on-site should not be problem. Self-discharge occurs naturally with NiCad or similar batteries and depends upon cell temperature. If you do not use batteries often (once a month for example), or store batteries as spares/stock, a battery cycling program is necessary. You should cycle (discharge/charge) spares, which could lie unused for weeks, once a month. Ensure batteries are labelled or numbered so you can identify a specific battery that is starting to show poor performance. Filters and Lens Accessories for Thermal Cameras Filters - Filters for thermal imaging cameras fit in front of the lens and work by reducing the transmission of certain thermal frequencies to the sensor. They are used for a number of purposes:- • High temperature filters act to limit the amount of radiation that reaches the sensor so that high temperatures can be measured without sensor saturation. • Flame filters remove infrared frequencies that are common on fuel-oil/gas flames, allowing the camera to ‘see through’ the flames to measure the component on a burner or in a furnace. • Other filters are available for viewing long distances or to help remove sun reflections. Lenses - Different lenses are available for thermal cameras to change the Field of View (FOV) angle. A smaller FOV lens will magnify an image to allow better image resolution at a greater distance. External Screen Accessories to Thermal Cameras Most cameras can be set up with external screens or monitors that can be used for a number of purposes. The typical purpose is to allow the camera to be located in a position that would not normally allow the viewing of an image by the operator. Video & Audio Attachments to a Thermal Camera Video Capture - Most thermal imaging camera can be attached to a video recording system. This can be used for a number of purposes:- • Where a detailed record of an inspection is required. • Where events may occur quickly and the camera operator could miss the manual capture of critical images • Where live thermal motions needs to be captured. • Where a very large number of thermal images are required. Audio Capture - Some thermal imaging cameras allow capture of short lengths of voice audio to be stored with a thermal image. This allows recording of information such as equipment names, maximum temperature, estimates of emissivity, defect type, recommendations and severity assessment. This can be done without interruption of camera use, making the inspection job easier and quicker and report creation easier. 5.8 Formal Thermal Imaging Reporting Thermal Images have high visual impact and are widely used as colourful eye-grabbers for reports and presentations.

Completion of an Initial Site Report Function of an initial site report • To communicate urgent issues to others who may need to take action • To communicate issues not directly relevant to machines monitored • To identified scope of work completed to customers • To leave a written record with plant area of the Thermal Imaging activity and the name of the person involved Use prepared site report sheet formats • Multiple copy site report form book o In machine and comment format. Has the advantage of automatic multiple copies. • A4 generic site report sheet Example o Requires carbon paper or photocopier to create a copy but can be modified to suit requirements o In machine and comment format. • Route specific machine list site report Example o In tick and comment format. Useful where information is required on each machine. Can be made reusable with a manual tend run-chart with synthetic paper. Completion of an Initial Site Report Site Report does not have to be detailed (2 or 3 item is OK). Should include: • Health, Safety, Security and Environmental (HSSE) observations • Other 5 senses observations not directly linked to monitoring activates eg. leaks, operational problem or problems with unrelated machines • Machines not collected and reason • Machines requiring urgent action (organise) Should be written by hand and completed before leaving the plant area. • Could be completed as you collect data in cleaner environments o Multiple copy form books assist with this as the top page can be discarded if it becomes dirty. Forms are in triplicate. o Must have a practical way to store form while collecting data • An option is to fill out report after completion of thermal collection from data recorded in your note book. o Don’t rely on memory Creating a Formal Thermal Imaging Report Download data to your computer to create the Thermal Imaging Report. Most Thermal Cameras use memory cards to store images. The memory card should be connected to your computer and the collected files transferred to a file folder. The folder is usually for thermal imaging data from an area. The photo files from the digital camera used during the inspection should be transferred to the same folder. The details below are instructions for ThermaCAM Reporter software. The details for other thermal imaging software will be similar. • ThermaCAM Reporter should be started by selecting Start/Programs/ThermaCAM Reporter. When the program starts a window called ‘New’ should open. If not select File/New. Also select Settings/File Locations & specify where you have located the files & where you want the report you will create to be located. • The files are imported into the report through a ‘Wizard’ (an automatic program). Select your desired template file from the template menu of the ‘New’ window. If this template is not there you need to locate a copy and copy it into C:\Program Files\ThermaCAM Reporter 99\Template. You may need help setting up a template to your requirements. • Follow the Wizards instructions & select appropriate files. Voice recorded notes can be reviewed. Voice of other notes for each item can be added such as section name, equipment name, recommendation and equipment load. • The help file for the ThermaCAM Reporter software will assist with its use. Select the highlighted text and view the following item: o Index/Wizard/Creating Reports using the Wizard – and view the menu items o If you have other questions about using the reporter or its tools, use the index to find answers • If you have successfully created the draft report view each image page and adjust or create the arrow to link a visual reference in the photo with a visual reference in the thermal image (the arrow should be a part of the template). • Click on the each box and point tool in the image and move them to the required temperature measurement location & reference of interest. The boxes can be resized by selecting a corner & stretching them. Note the maximum temperature in the box is recorded in the table. • If the temperature profile in the area of interest is not well defined by the colours, right click on the thermal image and select ‘Scale’. The maximum & minimum temperatures can be changed to vary the colour graduations. Also select ‘Settings’ to see the other data stored with the image. If you want to use more tools select Report/Unlock Layout. See the help file for these use. When all the information has been entered into the report and your Defect, Recommendation and Severity data has been added, print the report. If the report needs to be emailed, create an Acrobat pdf file and Email to others who may require the information. ISO Compliance for Thermal Imaging Reporting There is a proposed ISO standard specifying reporting requirements. • For all components and equipment, all thermal images must be accompanied by a photograph depicting the items contained within the thermal image; • All temperatures and profiles reported must have their measurement locations clearly reported; • For all measurements and profiles the emissivity used must be stated for each temperature reported whether it is assumed or designated; • You must identify the measurement location and the emissivity, whether assumed (i.e. 0.95 for the whole image) or designated (individually for a point). • All measurement conditions, such as distance from target, that affect the temperatures reported must be stated; • All reports must contain a statement of the operating conditions, such as load, under which the equipment was operating at the time of image acquisition; • All reports must contain a statement of the environmental conditions, such as humidity, under which the equipment was operating at the time of image acquisition; and • All reports must contain a defect diagnosis and a recommended action. Possible Thermal Inspection Applications • Electrical inspections in buildings, plants, refineries. • Thermal heat loss inspections for buildings, plants, facilities, refineries. • Moisture contamination evaluations in buildings, condo's, plants facilities • Concrete integrity inspections • Concrete Water Heated floor inspections for leaks & temperature distribution • Flat roof leak detection for buildings, plants, facilities • Power generation generator inspections. • Power Plant boiler flue gas leak detection • Substation Electrical inspections, transformers & capacitor evaluation • Over head urban & rural distribution electrical inspections • Electrical motor inspections, mechanical bearing inspections • Heat ventilation air conditioning equipment evaluation • Cold Storage cooling losses. • Refinery process line insulation loss or leak detection • Refinery process evaluation • Heat exchanger Quality & efficiency evaluation • Furnace refractory (insulation) inspections • Furnace Internal flame evaluation & tube inspections • Research and development applications • Design proto typing evaluation • Motor racing suspension & tire contact diagnostics • Brake & engine systems evaluation for performance & cooling efficiencies • Printed circuit board evaluation & trouble shooting. • Medical injury examinations for whiplash, back injuries, Carpal Tunnel • Diseases evaluation, breast cancer, arthritis & many more • Sports injuries & evaluation, & therapy progress • Equine (horse) injury examination, stress fractures, lameness • Airborne applications • Pipeline inspection, leak detection, stress corrosion cracking area • Environmental inspections, pollution dumping, thermal dumping of waste water • Fire Mapping, backburn, fire-line & mop-up insp. • High Voltage Aerial Electrical transmission lines • Search & rescue & Covert surveillance

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