Dräger Polytron 7000 Instructions For Use Manual page 29

4. Select Next.
 The current value and the gassing time are displayed.
5. When the displayed measured value has stabilised (max. wait time = 3 minutes),
perform the calibration.
a. Select calibrate.
b. Select Accept value.
c. End the target gas supply.
d. Select Back to menu.
6.5 Performing automatic calibration
Automatic calibration involves zero adjustment and span calibration in a combined
process. Automatic calibration can be used alternatively instead of separate zero
adjustment and span calibration.
Requirements:
– The automatic calibration function is activated (see section 11.2).
– The warm-up phase of the sensor is completed (see section 5.5).
– Test gas supply is prepared (see section 6.2).
Procedure, using an EC-O
The process of automatic calibration for EC-O
1. Select Calibration > Auto calibration.
 The 4-20 mA interface issues the maintenance signal.
 "Fresh air cal. is running!" is displayed.
 If the automatic calibration was successful, the message "EC-O
2. Select Back to menu.
Procedure, using an EC-H
1. Select Calibration > Auto calibration.
 The 4-20 mA interface issues the maintenance signal.
 The zero-point is adjusted. "Fresh air cal. is running!" is displayed.
 The values for the span calibration using the target are displayed.
2. Supply target gas.
 The target value, the current value and the sensor vitality (bar diagram)
are displayed.
 The calibration interval and the date for the next calibration are displayed.
Instead of performing zero adjustment, the zero-point value is checked. After
that, the sensitivity is calibrated.
displayed.
If the zero adjustment was successful, span calibration is performed.
Example:
"Cal.gas : H S
2
Cal.unit : ppm
Concentr.: 000025"
If the displayed values do not match the target used, use the control keys to
adjust the values to the target gas.
Dräger Polytron 7000
sensor as an example
2
sensors is shorter.
2
S sensor as an example
2
Calibration
: ok" is
2