8
GG-VL2-CO2
Span Calibration:
If span adjustment is required, use
the following procedure (see
Figure 2
):
• Unscrew calibration port cover and connect cal gas
hose to hose barb fitting.
• Press the CAL switch once to enter cal mode.
• Apply 5% CO2 span gas at 0.5 - 0.8 L/min.
• Sensor should react to gas within 15 seconds.
• Once the output signal has peaked (or 2 minutes
maximum) adjust the span pot until the correct
output is achieved (200 mVdc).
•
Shut-off gas, remove hose and replace cover.
• Press the CAL switch to exit cal mode.
• Calibration is now complete.
Note:
Depending on sensor’s proximity to fresh air,
allow up to an hour for the signal to return back to 4
mA after exposure to high concentrations. Applying
Zero Air calibration gas to the sensor will help purge
the CO2 gas from the sensor element, and return the
signal back to normal.
Note:
If correct output during span adjustment is
unachievable, replace sensor element. See sensor
replacement procedure on page 10 if a replacement
sensor element is needed.
