Manual

6 User Mode
GD-70D - 46 -
<Zero Adjustment "1-1">
This is used to perform the zero adjustment. Before starting the zero adjustment, let the detector suck the
zero adjustment gas and wait until the indicator is stabilized.
For oxygen deficiency alarm specification (OSU - 0 to 25 vol%), "1-1" is the span adjustment. In this case,
the AIR adjustment is performed, so that fresh air must be introduced to adjust it to 20.9 vol%. For
information on the span adjustment, see "7-2. How to perform a gas calibration".
Zero Adjustment
PW AL1 AL2 F LCD
1-1.ZERO
Press the SET key.
● ○ ○ ○
1- 1
ZERO
MAINTENANCE
↓ ↓
Current Concentration Value
Display
Press the SET key to perform the
zero adjustment.
● ○ ○ ○
1.1ppm
ZERO SET
MAINTENANCE
↓ ↓
Zero Adjustment Completed
The menu returns to 1-1.ZERO
automatically.
● ○ ○ ○
0.0ppm
ZERO OK
MAINTENANCE
↓
Return to 1-1.ZERO
* When the zero adjustment fails
● ○ ○ ○
0.0ppm
ZERO NG
MAINTENANCE
↓
Return to 1-1.ZERO