8.5Zero calibration (air point calibration in case of zirconia O2 sensor)
This is used for adjusting the zero point.
Flow the zero gas (0.3N/min.) by adjusting the needle valve of pressure regulator and wait until the indica- tion stabilizes.
When the Zirconia O2 sensor is used, use air.Note)
When the indication has stabilized, select the measur-
ing range to be calibrated by using the 
keys.
When using a
Press the ZERO key, and ZERO key lamp will flicker.
Next press the CAL key and conduct zero calibra- tion.
The CAL key lamp lights steadily during calibra- tion.
NO
ZERO
NO
Flickers
ENT ZERO SPAN CAL
CAL
NO
Lights
ENT ZERO SPAN CAL
ENT ZERO SPAN CAL
( Lamp is turned off after calibration )
Since the measuring status is resumed after the cali- bration, carry out the calibration for other ranges if necessary.
Note: When using different gases for the low and high ranges, apply 9 to 10 Vol. % O2/N2 which has been set for the low range.
When the function for automatic calibration is provided, the solenoid valve turns on and cali- bration gas flows upon pressing the ZERO key.
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