MicroRAE User’s Guide
28
9.3.1. Calibration
Use this menu to perform zero or span calibration for one or more sensors, and change the gas
concentration value assumed to be used in span calibration, as well as zero calibration and
calibration reference gas. Refer to “Calibration And Testing” on page 39 for guidance on setting
up the instrument for calibration.
9.3.1.1.
Single Bump
You can perform a separate bump test on each individual sensor.
The active sensors’ names are shown in a list. Press [MODE] to highlight the sensor you want to
bump test, and then press [Y/+] to select it.
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.
9.3.1.2.
Single Zero
This allows you to perform zero (fresh air) calibration on individual sensors. For most
applications, the instrument should be zero calibrated in clean ambient air with 20.9% oxygen
(0
2
). For more precise low 0
2
percentage accuracy, and after a new 0
2
sensor is put into the
instrument, zeroing should be performed with nitrogen (N
2
). 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.
9.3.1.3.
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 span calibration by pressing [Y/+]. If you do
not want to perform a span calibration, press [MODE] to quit.
