LumaSense Technologies INNOVA 1412i - Manual (Page 176)

Chapter 12
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BE6025-15 1412i Photoacoustic Gas Monitor LumaSense Technologies A/S
Page 176 of 202
water-vapour filter must be stored in the Monitor’s calibration data
block.
During span calibration of the water-vapour filter it is necessary to
attach a supply of zero-gas containing a known concentration of
water vapour to the Monitor. As explained in the Humidity-
interference Calibration ( Section 12.7.2 ) it is important to use water-
vapour whose concentration is below the saturated vapour pressure
of water-vapour at the temperature of the room where calibration is
to be performed, otherwise water-vapour will condense out in the
analysis cell and damage it.
Before setting-up the span calibration of the water-vapour filter go
into Set-Up mode and select “Tdew” as a humidity unit. Then when
you have to enter the concentration of the water-vapour you will use
during calibration. Always use water concentrations at least 2°C
below the ambient room temperature. For example, if the ambient
room temperature is 20°C then you can ENTER WATER-VAPOUR
CONC as 18°Tdew.
The procedure for setting-up a span calibration of the water-vapour
filter is as follows:
1. Press Measure S3 S3 S1 then the following text will be
displayed:
PERFORM ZERO-POINT CALIBRATION ?
NO YES
2. Follow the set-up of a span calibration of the water-vapour filter
by following the black arrows in the schematic diagram shown
in Fig.12.20 .
The following text will appear:
CONNECT WATER-VAPOUR 18.0 Tdew
AND PRESS ENTER WHEN READY