Honeywell AreaRAE Plus User Manual page 56

Single Sensor Zero
This allows you to perform zero (fresh air) calibration on individual sensors. Even though most
toxic gas sensors can be zeroed in fresh air, some sensors such as a parts-per-billion PID sensor
for volatile organic compounds (VOCs) should not be zeroed in fresh air. VOCs are normally
present in ambient air, so zeroing these sensors in ambient air will not allow for a true zero to be
set for such sensors. The parts-per-billion PID sensor should only be zeroed with zero air or in
ambient air using a charcoal filter or a VOC zeroing tube.
1. If you are using a charcoal filter, connect it to the instrument.
2. If you are using dry air, connect the instrument to a source of zero air.
3. At the Calibration Menu, select "Single Sensor Zero." Press [Y/+] once to enter the zero
calibration sub-menu.
4. Start the flow of zero air, if used.
5. Press [Y/+] to start zero calibration.
6. A countdown screen appears. You can abort the calibration at any time during the
countdown by pressing [N/-].
Note: Dotted line indicates automatic progression.
7. If the calibration is not aborted, the display shows the sensor names and tells you
whether the zero calibration passed or failed, followed by the sensors' zero calibration
readings.
Single Sensor Span Calibration
Instead of performing a span calibration on multiple sensors simultaneously, you can select a
single sensor and perform a span calibration.
Note: If a calibration icon (bottle with bottom portion filled in) is shown next to any of the
sensors, it means that the sensor is due for a full calibration.
To perform span calibration of an individual sensor, follow these steps:
1. At the Calibration Menu, select "Single Sensor Span."
2. Select a sensor to calibrate from the list.
3. Install the "T" tube and connect it to a source of calibration gas.
4. Verify that the displayed calibration value meets the concentration specified on the gas
cylinder.
5. Start the flow of calibration gas.
AreaRAE 55 User Manual