MicroRAE User’s Guide
42
11.3.
Span Calibration
This procedure determines the second point of the sensor calibration curve for the sensor.
Note:
When a manual calibration is performed, the readings shown are in the equivalent
units of the calibration gas, and not the measurement gas.
When performing a Span
calibration, the Calibration Adapter must be used for supplying calibration gas to all sensors at
one time:
1.
Align the Calibration Adapter’s main body with the indented area around the MicroRAE’s
gas inlets.
2.
Turn the knob clockwise to secure the Calibration Adapter to the instrument.
3.
Connect the hose to the Calibration Adapter and to its gas source.
4.
Make sure the Calibration Adapter is securely attached before starting the flow of
calibration gas. (The Calibration Adapter has small grooves on its underside to allow gas to
escape after passing over the sensors.)
11.3.3 Multi-Sensor Span Calibration
This lets you perform a span calibration on multiple sensors simultaneously. It requires using the
appropriate span gas and that the concentration labeled on the gas cylinder matches the
concentration programmed in the MicroRAE.
1.
Start the flow of calibration gas.
2.
Attach the calibration adapter and gas to the MicroRAE.
3.
Press [Y/+] to begin calibration. A countdown screen is shown. You can abort the
calibration at any time during the countdown by pressing [MODE].
If the calibration reaches its conclusion, it shows the sensor names and tells you whether the
calibration passed or failed, followed by the sensor readings.
11.3.4. Single-Sensor Span 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 from the list.
3.
Start the flow of calibration gas.
4.
Connect the calibration adapter and connect it to a source of calibration gas.
5.
Verify that the displayed calibration value meets the concentration label on the gas
cylinder.
