Understanding Temperature Modes Part 2
Understanding Temperature Modes Part 2:
We began our series by emphasizing the importance of recognizing the difference between high and low sensitivity and how that affects the victim, the environment, and firefighters.
In this example, we will show two different fire service thermal imaging cameras to demonstrate that just because we understand the concept of temperature modes that doesn’t mean we understand when our TIC switches modes and the associated color/temperature correlations.
In the first example, we are viewing a small fire in a burn building with a Bullard NXT. The Bullard NXT switches from high to low sensitivity when 3% of the pixels within the overall field of view are at 230 degrees Fahrenheit. Notice how fast the TIC switches between high and low sensitivity!. Notice the difference in high and low sensitivity. In high sensitivity, we see no colorization but increased detail and clarity. In low sensitivity, colorization engages beginning at 500 degrees Fahrenheit with yellow. Also notice in low sensitivity, there is a loss in detail outside of the heat source. This is common in all fire service TIC’s when they switch to low sensitivity. As we learned in part 1, Low Sensitivity Range which is defined by NFPA 1801 as:
“The least thermally sensitive operational mode, used to increase the thermal imager’s temperature range” NFPA 1801 Section 3.3.24.1
In other words, in Low Sensitivity there is an increase in temperature and loss in image clarity.
In the second example, we view our friends from overseas performing a similar demonstration with an MSA 6000 TIC. This model shows colorization in both high & low sensitivity. However, notice when the TIC switches to low sensitivity what disappears? The colorization that was visible in high sensitivity is now replaced with greyscale moving convection currents. This is due to the following fact:
MSA 6000 does not switch from high to low sensitivity until 32% of the pixels are at or above 270 degrees Fahrenheit.
MSA 6000 shows colorization in both high and low sensitivity. In High Sensitivity, the MSA shows colorization beginning at 291-311 degrees Fahrenheit. But in Low Sensitivity, colorization will not begin until 1000 degrees Fahrenheit.
Therefore, we may understand the concepts of temperature modes or gains but we must also understand OUR THERMAL IMAGING CAMERA.
When does it switch from high to low sensitivity?
How many pixels does it require before it switches from high to low sensitivity? This is important! As the more it requires to change gains/models the closer to the heat source we will actually have to be.
When does colorization engage?
May we learn our thermal imaging camera and use it to its maximum efficiency.
Stay Intelligently Aggressive!
Instructor Andy Starnes
Insight Training LLC
Thermography Certified Fire Service Professionals