Heath Consultants Gasurveyor 500 Series - Manual (Page 14)

GASURVEYOR 3-500 USER HANDBOOK
4
Volume Gas, 0 to 100 %
This range displays the total volume of a specific
flammable gas with respect to air. The calibration gas is
shown on the service label and for the purpose of this
handbook is assumed to be methane. Instruments
calibrated for methane in air should only be used for
measuring such mixtures. To change the calibration gas,
e.g. from methane to propane, the instrument must be
recalibrated by suitably trained personnel.
On the Volume Gas range the instrument range is
displayed in the top right corner of the LCD as GAS. The
digital display resolves the signal to 1% GAS with the
analogue bar graph following in steps of 4%. Figure 2.2
shows the Volume Gas display. The detection principle
for the Volume Gas range is thermal conductivity.
When using PURGE mode to measure flammable gas in
air or Nitrogen, or a combination of both background
gases, the Gasurveyor 3-500 will use the thermal
conductivity Volume gas range only.
The digital display will resolve the signal to 1% Gas, with
the analogue bar graph following in steps of 4%.
Figure 2.2 Volume Gas Range