PROGRAMMING OF IAQRAE
4-8
4.2.2 Multiple Sensor Calibration
This function simultaneously determines the second point of
the calibration curves for multiple sensors in the monitor. Mixed
standard reference gases are needed to perform this
procedure. The user may choose several gas mixtures to be
used in multiple sensor calibration.
1. Continuing from Step 4 of the previous section, the next
display “Multiple Sensor Calibration?” will appear. Press
[Y/+] and the display will ask “OK?” for the pre-selected
gases indicated by an asterisk. To accept the multiple
sensor selection, press [Y/+] to start calibrating. To abort
calibration, press [N/-] and move to the next submenu,
Single Sensor Calibration.
To modify the default setting
, press [MODE] to move
from one sensor to the next. Press [Y/+] to select a sensor
and [N/-] to deselect a sensor. The selected sensors will
have an asterisk (*) next to the name. Repeat, until all
sensors that need to be calibrated are selected. To confirm
the new selection, press [MODE] to move the cursor to
“OK?”, then press [Y/+] to accept the changes and
advance to the next step. To discard the changes, press
[N/-] to exit the submenu.
*CO
VOC
*CO
2
RH
OK?
Temp
2. After pressing [Y/+] in step 1, the monitor will ask the user
to apply mixed gas to the sensors. The calibration adapter
allows any excessive gas to escape without over-
pressurizing the pump which supplies gas to the sensors.
The adapter lets the pump draw gas at the same rate
atmosphere is usually provided to by the pump to the
sensors.
Note:
The 350 ppm CO
2
present in ambient air is not
enough to calibrate the CO
2
sensor. Therefore, if the CO
2
sensor is enabled in the instrument and no gas flow exists,
there will not be a span signal and the “no gas flow”
message will appear.
