PROGRAMMING OF VRAE
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4.4.3 Single Sensor Calibration
This procedure determines the second point of the sensor
calibration curve for a single sensor. A bottle of standard
reference gas (span gas) is needed to perform this
procedure. Table 2.2 shows the standard calibration gases
typically used as span gases in the factory. Snap in the
calibration adapter over the inlet port of the VRAE monitor,
and connect the tube to the regulator of the gas bottle as
shown in Figure 4.4.1
1. Continuing from Step 4 or Step 6 of the previous section,
the display should show “Single Sensor Calibration?”
Press
[Y/+]
key. The display shows all the installed
sensors in the monitor with the cursor blinking at the
first sensor location. Press
[Y/+]
key to select the high-
lighted sensor and start the calibration, or press
[MODE]
key momentarily to move to the next sensor
location.
CO
SO
2
H
2
S
LEL pick?
OXY
2. Turn on the valve of the CO gas bottle to start the flow of
the span gas. Display shows “Apply CO Gas” and the
span value set. The VRAE monitor will wait for the
calibration gas to reach the sensor. When the calibration
gas has reached the sensor the display will show
“calibration in progress… 60” with the countdown timer
shows the number of remaining seconds while the
monitor performs calibration. When the countdown
timer reaches 0, the display shows the sensor name and
the calibrated value:
