OMGEMN1.41
GEM2000 Range Gas Analysers
Page 32
Copyright 2009 Geotechnical Instruments (UK) Limited
7.3 The Gas Flow Measurement Screen
The GEM2000 range gas analysers enable gas and flow measurements to be recorded by
using the following methods:
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An anemometer.
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A pitot tube.
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An Orifice plate.
The GEM2000 range has the extra functionality to measure the calculated calorific values
of the gas. The site engineer uses the information recorded by the analyser to make
adjustments to the gas flow for specific boreholes. The initial and adjusted flow rates are
recorded.
The initial and adjusted flow rates are displayed on the ‘Gas Flow Measurement Screen’ as
shown below:
Adjusted Reading
‘Adjusted’ displays the final reading if adjustments have
been made to the ‘Initial’ reading. ‘Adjusted’ readings
become the ‘Previous’ reading next time.
Initial Reading
‘Initial’ displays the values for the reading that has just
been taken.
Previous Reading
‘Previous’ displays the previous measurement readings for
the selected borehole ID.
Tips When Taking a Measurement:
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When taking a gas flow measurement a prompt is displayed to ensure all tubes are
disconnected, as a clean air purge will automatically be carried out at this point to
ensure the previous sample is purged from the analyser.
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The borehole ID number selected and the run-time are displayed in the upper left
corner of the ‘Main Gas Read Screen’.
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When attaching fittings to the connector ports ensure that they click into place.
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As soon as a connection is made the relative pressure reading will be displayed.
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The pump will run for a pre-programmed time and a countdown timer will be
displayed. The pump may be stopped and started at any time. Whilst the pump is
running the analyser continuously monitors the peak readings.
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Pre-programmed questions may require numeric, alphanumeric, selectable comment
or exclusive comment.
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For ‘No ID’ readings the ID code information will be stored as ‘ ---------‘.
