Infrared continual gas analyser uses correction circuit - eliminates errors due to changes in gas concn. and temp. of ambient air

摘要

An infrared gas analyser continually determines the concn. of a multiatomic non-elementary gas by means of an absorption cuvette which receives the gas for analysis, two interference filters, a radiation receiver to measure the absorbed radiation, while the gas under analysis is concentrated, and a radiation receiver to generate a reference signal. The novelty is that the receiver (7,8) signals pass through an amplifier (1,2), a rectifier (3,4) low-pass filters (5,6), are then passed through a circuit (10,11), where they are corrected by a signal indicating the condition of the radiator source (13) via an amplifier (9), such that the difference at the output of the differential cirucit (12) has a constant value when no gas concn. is present and when there is a variation in the temp. of the ambient air. The radiating source (13) is activated by an electrical timing circuit (14). The signal denoting the radiating power passes through a primary resistor (15). The corrector circuits (10,11) are multiplier or divider circuits. The corrector circuits (10,11) incorporate addressable readable memory. The infrared radiation from the source (13) must pass through one or more filters (16). USE/ADVANTAGE - The equipment continually determines the concn. of a multi-atomic non-elementary gas by means of infra-red analysis. Changes in gas concns. and ambient air temp. have no effect on the accuracy of measurements.