The air humidity effect on the detection of TNT, PETN and NG by the FAIMS technique

- Air humidity affects the FAIMS detection of different explosives.
- With growing humidity of ambient air the decline in TNT signal level was observed.
- Detector signal is rising with air humidity in the presence of NG and PETN vapors.

The effect of air humidity on the effectiveness of the detection of trace amounts of explosives was studied using the detectors based on the FAIMS technique. Two detectors employed: PILOT-M and MO-2M differed by the way the air containing NG, TNT, or PETN vapors was ionized. The air humidity level was found to affect sensitivity of the detectors used in a different manner. In detecting TNT vapors a rise in the air humidity level results in a drop of the signal level, whereas for PETN the signal rises for either detector. This is of major significance when working with the detectors for the explosives vapors detection based on the FAIMS technique.