Oxygen sensor moves between a calibration point and an operating position within a void filled by a potentially explosive atmosphere

摘要

The chamber void has a movable oxygen sensor linked to a measurement instrument, a fluid inlet, a fluid outlet, and a mechanism which transports the sensor from a first position in which it makes contact with the fluid, to a second position within the calibration and conditioning chamber separate from the fluid void. The calibration unit is a data processing system which operates and regulates the transport mechanism, oxygen content within the calibration and conditioning chamber. The calibration system registers the oxygen content when the sensor reaches the second position. The fluid inlet tube is fed by a supply of rinsing agent, a water-moistened gas and a calibration gas containing oxygen. The oxygen sensor is attached to a movable support from which it may be detached as required. The assembly further incorporates an indicator revealing the sensor condition during and/or after the calibration process. Also claimed is a process to determine the oxygen content in the chamber.