Output stability or drift overtime has long been a major
performance deficiency for gas sensors irrespective of what technology or
methodology is used for their conception. Software correction may alleviate the
problem somewhat but it is not always applicable. It has long been the
objective of many researchers in this field to overcome this problem
fundamentally and for good. The purpose of this paper is to show that this
objective has now finally been achieved.
Design/methodology/approach
– Conventional non‐dispersive infrared (NDIR) dual beam methodology
utilizes the ratio of signal channel output over reference channel output for
signal processing. The signal filter overlaps the absorption band of the gas of
interest while the reference filter does not. However, this ratio changes as
the source ages. The current methodology uses an absorption bias between signal
and reference channel outputs. This absorption bias is created by using a path
length for the signal channel greater than that for the reference channel. Both
the signal and reference detectors carry an identical spectral filter
overlapping the absorption band of the gas to be measured.
Findings
– Implementation of the currently patented NDIR gas sensors methodology has been carried out in different
gas sensor configurations for over a year in the laboratory. Performance
results for these sensors showing insignificant output drifts overtime have
been repeatedly demonstrated via simulated aging for the source.
Originality/value
– The paper puts forward the view that the recent
breakthrough of the Near Zero Drift methodology for NDIR gas sensors will very
quickly change the hierarchy of technology dominance and utility for gassensors at large.
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