Rae QRAE 3, User Manual, Page: 23 / 71

20
When the Apply Gas screen is shown, connect the calibration gas to the instrument, and start the
bump test by pressing [Y/+]. If you do not want to perform a single bump test, press [MODE] to
quit.
Note:
You can abort a bump test by pressing [MODE] once testing has started.
When the Multi Bump test is done, a screen is shown, with the sensor names and either “Pass” or
“Fail” shown next to them.
8.3.2.5. Single Zero
This allows you to perform zero (fresh air) calibration on individual sensors. The instrument
should be zero calibrated in clean ambient air with 20.9% oxygen. A zero calibration should
precede a span calibration.
The active sensors’ names are shown in a list. Press [MODE] to highlight the sensor you want to
zero calibrate, and then press [Y/+] to select it.
When the Zero Calibration screen is shown with the sensor name and its measurement unit, start
the zero calibration by pressing [Y/+]. If you do not want to perform a calibration, press [MODE]
to quit.
Note:
You can abort a zero calibration by pressing [MODE] once testing has started.
When the zero calibration is done, the Calibration Results screen is shown with either “Pass” or
“Fail” shown.
8.3.2.6. Single Span
Instead of performing a span calibration on more than one sensor simultaneously, you can select a single
sensor and perform a span calibration.
The active sensors’ names are shown in a list. Press [MODE] to highlight the sensor you want to
span calibrate, and then press [Y/+] to select it.
When the Apply Gas screen is shown with the sensor name and its measurement unit, connect a
cylinder of span gas, start its flow, and then start the zero calibration by pressing [Y/+]. If you do
not want to perform a span calibration, press [MODE] to quit.
Note:
You can abort a span calibration by pressing [MODE] once testing has started.
When the span calibration is done, the Calibration Results screen is shown with either “Pass” or
“Fail” shown.
8.3.2.7. Set LEL Cal. Gas
For best response, it is desirable to calibrate an LEL sensor with the specific gas that you are
surveying (target gas). Changing the gas requires selecting the right calibration reference gas in
the QRAE 3. Choose the sensor, and then select from the list of reference gases. Select from a
Custom Gases list that you create or the built-in Gas Library for your sensor (taken from RAE Systems’
Technical Note TN-156 or the table at the end of this user’s guide).
Choose Custom Gases or Gas Library by pressing [MODE], and then press [Y/+] to make your selection.