Calibration
Dräger Polytron 8700/8720 15
z Actual value within the permissible range:
{ Select Next and confirm.
{ Shut off the test gas and remove the calibration adapter
from the PIR 7000/7200.
z Actual value outside the permissible range:
{ Select Next and confirm.
{ Wait until the measurement is stable.
5.1.2 Span calibration
1. Select Calibration > Span calibration and confirm.
The Maintenance signal is transmitted.
The values for the calibration gas are displayed, e.g.:
All three paramrters can be changed:
z Select Gas and confirm.
{ Select the desired calibration gas from the list and
confirm.
z Select Unit and confirm.
{ Select the desired unit from the list and confirm.
z Select Conc. and confirm.
{ Set the desired concentration of the calibration gas.
When the settings are correct:
2. Select Next and confirm.
A message such as, e.g. Gas flow to METHANE
is displayed.
3. Connect the calibration gas to the sensor.
4. Select Next and confirm.
The current value is displayed.
After the displayed value is stable:
5. Select Next and confirm.
The message Please wait… is displayed.
The actual value is displayed.
z Actual value within the permissible range:
{ Select Next and confirm.
{ Shut off the test gas and remove the calibration adapter
from the PIR 7000/7200.
z Actual value outside the permissible range:
{ Select Next and confirm.
{ Wait until the measurement is stable.
z A calibration can be aborted at any time.
5.2 Performing Auto Calibration
The device offers the option of an automatically sequenced
calibration. This reduces the number of otherwise manual
interactions with the device. The auto calibration is only
suitable for experienced users, as calibration errors can occur
here as a result of tightened procedures.
1. Select Settings > Sensor > Autocal. set. to enable or
disable the function.
2. Supply fresh air or feed nitrogen or compressed air at
a flow rate of 0.5 - 2.0 L/min to the sensor.
3. Select Calibration > Auto cal. and confirm.
{ Please wait... is displayed and a calibration of the zero
point is performed automatically.
{ After a successful zero point calibration, the span
calibration is started.
{ The calibration gas concentration, the units and, where
appropriate, the calibration gas are displayed and can
be changed.
4. Start the calibration with Next; Back to menu aborts the
calibration.
5. Feed the relevant calibration gas to the sensor at a flow
rate of 0.5 - 2.0 L/min.
{ When the measured value is stable, the device performs
the calibration automatically.
{ After a successful calibration, the measurement and
the message Value OK? are displayed.
6. When the measurement is stable, shut off the calibration
gas and wait until the measurement is below any possible
alarm thresholds again.
z The calibration is performed again with Redo.
z Complete the calibration with Accept value.
The device returns to the measurement mode.
Gas Methane
Unit %LEL
Conc. 50.0
NOTICE
Not all of the available sensors and gases support auto
calibration. If the function is not available, a manual
calibration must be performed.
WARNING
It must be insured that during the zero point calibration,
no measured gas is present in the supplied calibration
gas. Particularly with a fresh air calibration, Dräger
recommends performing a second, independent
measurement. Some sensors may only be calibrated
with synthetic air or nitrogen (observe the relevant
sensor data sheets).
NOTICE
After 10 minutes without confirmation, the device
reverts to measurement mode without performing
a calibration.
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