Patent ID: 7146841

Claim:
An apparatus for calibrating at least one sensor within a portable gas detector, which detector has a gas inlet in fluid communication with the at least one sensor, the apparatus comprising a housing that contains: a) a surface for abutting against a gas detector; b) a holder for holding the gas detector with respect to the housing in such a manner that a region of the detector containing the gas inlet abuts against the surface of the housing to form a sealed gas intertace between the surface and the detector; c) a connector for connecting a source of pressurized calibration gas to the apparatus, d) a conduit for delivering calibration gas from the connector to the interface between the detector and the apparatus housing, e) electrical connectors within the holder for forming electrical connections between the apparatus and the detector held within the holder, and f) a flow controller within the conduit for providing calibration gas at a predetermined level to the interface, the flow controller including an electrically-operated flow control valve which is controllable for initiating and terminating a flow of calibration gas through the conduit by valve control signals received by the valve from the detector via the electrical connections.