ACOEM Met One Instruments GAS-1060, User Manual

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Serinus 60 User Manual 3.0
Page 24
and this will be reflected as a change in phase of the vacuum photodiode detector signal. This change
in phase of the vacuum photodiode detector signal is a measure of NO
2
concentration.
Using this principle it is possible to reliably measure NO
2
concentrations of well under 1 ppb and up
to 1000 ppb. Due to the continuous measure of the sample stream the Serinus 60 NO
2
analyser has a
fast response time of less than 30 seconds.
1.5 Instrument Description
The major components of the Serinus 60 are described below:
Figure 2 – Internal Components Diagram
1.5.1 Calibration Valve Manifold
The calibration valve manifold switches between sample, calibration and background gas.
1.5.2 Background Scrubber DAU
The background scrubber disposable absorbent unit (DAU) is a replaceable activated carbon scrubber
used to remove NO
2
from the sample stream during an automatic or manual background
measurement. It is also utilised during and internal zero calibration mode.
1.5.3 Sample Filter Holder
Within the sample filter holder is a particulate filter. The particulate filter is a Teflon 5 micron (µm)
filter with a diameter of 47mm. This filter eliminates all particles larger than 5µm that could interfere
with sample measurement. The 5 micron filter element should be replaced on a regular basis.