AreaRAE Plus & AreaRAE Pro User's Guide
12.3.10 LEL Calibration Procedure
You must perform a separate zero calibration for the LEL sensor and then perform a span calibration.
Important! Before calibrating, make sure pump is on its high setting. This is in the "Pump Speed" submenu
under the "Monitor" menu item.
To calibrate the LEL sensor, follow these two procedures:
Zero Sensor Calibration For The LEL Sensor
1. Turn on the AreaRAE Plus/Pro and allow it to warm up for 20 minutes in ambient air.
2. In Programming mode, Select "Calibration" and then select "Single Sensor Zero."
3. Select "LEL."
4. Calibrate the LEL sensor's zero point with ambient air.
5. After zero calibration is complete, press [MODE] to return to the Calibration menu. "Single
Sensor Span" is highlighted
Span Calibration For The LEL Sensor
1. Press [Y/+] to select "Single Sensor Span."
2. Press [N/-] until "LEL Sensor" is highlighted.
3. Press [Y/+] to select "LEL Sensor."
4. Screw one end of a "T" using Teflon tubing to the AreaRAE Plus/Pro filter on the inlet. (You can use
RAE Systems P/N: W01-3003-000).
5. Attach the other end to the flow regulator of a calibration cylinder with 50% LEL methane (unless
otherwise specified ). The flow rate should not be less than 750cc/min.
6. Start the flow of calibration gas.
7. Press [Y/+] to start calibration.
8. When calibration is complete, shut off the calibration gas flow and disconnect the calibration tubing.
9. Press [MODE] to exit to the menu. (You may perform other calibrations. Otherwise, exit.)
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