LumaSense Technologies INNOVA 1412i - Manual (Page 172)

Chapter 12
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BE6025-15 1412i Photoacoustic Gas Monitor LumaSense Technologies A/S
Page 172 of 202
be cut in half and a tubing should be connected between the two cut-
ends of the teflon tubing using the tube fittings supplied for the
purpose (Fig.12.18).
Fig.12.18 Diagram showing how to use Nafion tubing when span
calibrating with one of the following optical filters: UA0983, UA0984
or UA0985
12.10 Calibration of the Water-vapour Filter – Stand-
alone Use
The water-vapour filter has two different functions. Its most
important function is to enable any measured signal to be
compensated for water-vapour interference. Its other function is to
measure the absolute concentration of water-vapour in air samples.
If you only wish to use the water-vapour filter to compensate for
water-vapour interference, then it only has to be zero-point
calibrated. If you wish to use it to measure the absolute
concentration of water vapour in air samples then it has to be zero-
point calibrated and span calibrated.
It is vitally important to accurately zero-point calibrate the water-
vapour filter as this influences the Monitor’s ability to compensate for
interference from water vapour. This demands that the zero-gas you
use during the zero-point calibration of the filter must be perfectly
dry.