GAS SENSOR CALIBRATION SYSTEM

摘要

The present invention provides a method of calibrating sensors within a gas detector (36) having a housing containing a gas inlet whereby gas can diffus e from the inlet to the sensors. The gas inlet in the housing is held against part (34) of the calibration apparatus to form a sealed gas interface betwee n the apparatus and the detector; a source (10) of pressurised calibration gas is connected to the apparatus, and a predetermined dose of calibration gas i s delivered to the interface between the detector (36) and the calibration apparatus (34) at a predetermined pressure. The source (10) of pressurised calibration gas may contain single or multiple calibration doses and, if the former, the calibration apparatus includes a dosing system such as cylinder (14) for metering individual doses of calibration gas.