Abstract: A respirator has one or more electrodes of e.g. conductive elastomer disposed on the surface of a face sealing member opposite to the surface which seals against the user's face. In use the integrity of the seal formed between the sealing member and the user's face is monitored by monitoring the electrical capacitance across that member between the electrode(s) and the user's face.

Abstract: A respirator has one or more electrodes of e.g. conductive elastomer disposed on the surface of a face sealing member opposite to the surface which seals against the user's face. In use the integrity of the seal formed between the sealing member and the user's face is monitored by monitoring the electrical capacitance across that member between the electrode(s) and the user's face.

Abstract: An RF screening apparatus comprising a scanning chamber and an RF inspection device or reader, the chamber having chamber walls which are substantially reflective to radiation at a frequency of operation. The chamber walls or at least a portion of the chamber walls may be visually transparent. This enables visual inspection and identification of the occupant and RF interrogation to be performed, substantially simultaneously if desired. RF interrogation signals produced by the reader reflect off the chamber walls, approaching a target tag from an increased number of different angles, thus increasing the chance of a successful read.

Abstract: A device for attenuating electromagnetic radiation in a desired transmission frequency band. The device includes a generally planar substrate, and a resistive pattern arranged on the substrate adapted to reflect a proportion of incident radiation in the transmission band. The resistive pattern may be screen printed using carbon based ink. This provides a simple, cheap and easy to fabricate device which can quickly and easily be affixed to the exterior of an antenna or antenna housing to attenuate the power of radiation in the transmission band, resulting in reduced range or sensitivity.