Publications Details

Laboratory evaluation of the PCP Large Reaction Volume Ion Mobility Spectrometer (LRVIMS)

Schellenbaum, R.L.

The PCP, Inc. Large Reaction Volume ion Mobility Spectrometer (LRVIMS) was characterized and evaluated for use as a contraband explosives vapor detector in personnel and package portal screening applications. The limit-of-detection was found to be a constant {approximately}0.3 PPT experimentally and in calibrations using a Thermedics RDX generator. The minimum LOD in terms of RDX vapor molecular flow rate was {approximately}1.8 {times} 10{sup 9} molecules/sec at 16.6 L/min airflow through the 100 cm{sup 2} square tube area of this ion mobility spectrometer. Samples of 0.5 gm of TNT in plastic bags in the center of the personnel screening portal were easily detected. Bomb quantity (8 oz) samples of TNT and Comp B (40% TNT, 60% RDX) were also detectable in the personnel portal configuration. No detections of RDX were possible in any position of either C-4 or Comp B or of PETN in Detasheet or Det Cord. Operation in the presence of observed background interferants, operation at very low airflow rates, and proposed operation in conjunction with preconcentrators, also are described. 14 figs.