ASTM E1543 Noise Equivalent Temperature Difference of Thermal Imaging Systems

Scope

ASTM E1543 is useful in providing an objective assessment of a thermal imaging system’s temperature sensitivity without a monitor, with a focus on the detector(s) and preamplifier. This test technique is also important in occasionally observing the performance of a given thermal imaging system.

Procedure

In this ASTM E1543 test method, a blackbody source of uniform temperature is observed by an infrared thermal imaging system using an aperture. A particular temperature difference is formed between the target and the background. The peak-to-peak signal voltage from the target and the RMS noise voltage from the background are both measured and then NETD is calculated.

Video 01: Thermal Imaging

Specimen size

For ASTM E1543 testing, the specimen temperature difference should be between 5 and 10 °C.

Data

Noise Equivalent Temperature Difference, NETD is calculated as follows.

NETD = T ­ T_B ÷ S/N (°C)

where: 

T = target temperature (°C), 

T_B = target background temperature (°C), 

and S/N = signal to noise ratio (dimensionless).

Conclusion

Noise Equivalent Temperature Difference of Thermal Imaging Systems is determined by this ASTM E1543 test method and its purpose is to monitor the performance of thermal imaging systems.