horiba APNA-370, Operation Manual

Page: 39 / 113

4 CALIBRATION
27
4.4.2 Zero calibration
1.
On the CAL. screen, check that the proper measurement line is selected.
If necessary, press the displayed MODE setting on the CAL. screen to display the
MODE screen, and then change the setting and press the [SET] key on the MODE
screen.
When using the calibration gas line: Select [ZERO].
When using the measured gas line: Select [MEAS.].
Fig. 36 MODE screen
2. When using the measured gas line, supply the zero gas from the sample gas inlet.
3.
Wait for the readouts to be stabilized and then press the [ZERO] key on the CAL.
screen. The zero calibration message will be displayed.
Fig. 37 Zero calibration message
Note
The [ZERO SET] key on the CAL. screen is valid only when MODE is set to MEAS. or ZERO.
4. Press the [YES] button. The zero calibration will be started. After the calibration is
completed, the zero calibration coefficient will be updated and the CAL. screen will
be displayed again.
Tip
To return the CAL. screen without executing zero calibration, press the [NO] button of the zero
calibration message.
Note
If the result of the zero calibration deviates from the allowable range of zero calibration (±3500
counts), the ZERO (zero calibration) alarm occurs (see “8.2 Alarm List” (page 83)) and the zero
calibration coefficient is not updated. In this case, the zero calibration coefficient displayed on the
CAL. screen blinks. And if the standard output terminal block is provided, the alarm contact signal is
outputted. See the rear panel signal table at the end of this document.