By Teledyne ICM
For EOD teams, the use of PIR (Passive Infrared) sensors in explosive devices can be a major concern as they are sensitive to X-Ray, and then can trigger a device while performing the inspection.
The classic X-Ray method used does not allow to manage kV then it becomes very difficult to be undetected by PIR. With the technology evolving, Constant Potential X-Ray generators have appeared and allow to adjust kV and mA while being able to set the duration of a shot. When having the parameters of
the generator set to low kV and mA, we can remain undetected by PIR sensors.
To prove this theory, we have conducted a study to determine the operability of CP (Constant Potential) Battery operated generators below the sensor sensitivity while keeping a sufficient image quality.
SAMPLE OF PIR SENSORS
For this study, a non-exhaustive sample selection of PIR sensors has been used:
- Adjustable kV, mA and exposure time
- Compatibility with X-Ray Scanners and Amorphous Silicon digital detectors
Target: identifying triggering limit versus operating conditions based on kV and mA, distance and duration.
a. Effect on duration
- PIR Sensor: Chacon
- 120kV, 0.25mA (Full power)
While shooting at full power of the LiteX generator, the PIR sensor triggers immediately when x-rayed, the duration has no effect even at 1 second.
b. Effect of kV – mA adjustment
- PIR Sensor: Chacon
a. Image quality using TactX with LiteX
c. Corrected image quality using TactX with LiteX – SNR Value
Constant potential generators can operate below PIR triggering limit while having a good average flux and an excellent image quality because:
- Signal is continuous
- Focal spot is smaller
- kV and mA are adjustable
- Time is adjustable
So, when PIR systems are used, the best way to not trigger them is to decrease kV and mA but increase exposure time. This will offer a great image quality while remaining undetectable. ■
ABOUT TELEDYNE ICM
Teledyne ICM has over 25 years of expertise in developing innovative portable radiography solutions. Its portable generators have excellent technical capabilities and when coupled with high-resolution detectors, provide highly accurate radiographs.
Counter-IED Report Spring/Summer 2023