When choosing the right model of the camera, complex parameter comparisons such as image resolution, camera sensitivity and temperature range are often required. In short, the temperature range indicates the lowest temperature and highest temperature that a thermal imager can measure.
What you should know about the wide temperature range of thermal imaging cameras
1. Dangerous image quality loss
The term ‘temperature range’ is somewhat misleading. More important for firefighters is the effective temperature range (ETR), which measures the temperature range that the thermal imaging camera can observe and provides useful information to the user.
Fire imaging cameras typically have a high sensitivity mode and a low sensitivity mode. In an environment where there is no fire, the thermal imaging camera will operate in a high sensitivity mode, revealing all the details of the thermal environment.
The maximum temperature that the FLIR K Series cameras can measure in high sensitivity mode is +150 °C. At the scene of the fire, the camera will switch to a low sensitivity mode, providing an acceptable balance between low sensitivity (less detail) and the ability to monitor higher surface temperatures. The maximum temperature that the FLIR K Series cameras can measure in low sensitivity mode is +650 °C.
When measuring higher temperatures (ie over +650 °C), the camera will switch to a lower sensitivity mode (the so-called third gain mode), which can measure higher temperatures but sacrifice image detail At the expense of contrast, resulting in unacceptable loss of image quality. The third gain mode may block firefighters from seeing the victim, colleague or escape route, which is a serious safety and rescue problem.
2. A glimpse of predicting flash fire
Thermal imaging cameras are sometimes thought to predict flash fires, which is not the case. Flash fire occurs when the air temperature is much higher than +500 °C. Even with an infrared camera with a maximum temperature measurement above +500 °C, flashing cannot be predicted because the camera detects the surface temperature, not the air temperature.
There is no clear answer as to why flashing occurs. Flash fire is almost unpredictable, and flash fire may not occur even under ideal/typical conditions where flash fire occurs. Thermal imaging cameras may be useful in identifying flash precursors through sophisticated image interpretation. But by far the only way to guard against impending flashovers is through comprehensive training or careful observation of the environment.
3. What is the predicted steel structure to be melted?
It is said that thermal imaging cameras sometimes predict when steel will begin to melt and bend. This may be especially useful for fire application scenarios where there are industrial buildings that often employ steel frames. However, this would be very difficult to achieve, even with the help of a thermal imager capable of measuring +1, 100 ° C at the highest, because the melting point of steel is actually higher (+1,400 ° C).
Under what circumstances does the wide temperature range make sense?
Unlike fire-fighting thermal imaging cameras, high-temperature readings in many applications make sense. In industrial and manufacturing environments, FLIR thermal imaging cameras are used to monitor the fire resistance of boilers and furnace equipment through flames. Thermal imaging cameras such as the FLIR T640 can read temperature values between -40 ° C and +2,000 ° C with an accuracy of ± 2% of reading.
High temperature performance is critical in some R&D environments such as microelectronics, automotive, plastics and mechanical testing. FLIR has introduced a number of scientific imaging cameras that recognize subtle temperature changes as small as 0.02 °C from -80 ° C to +3,000 ° C.