Calibration; General; Possible Ways Of Calibration For The Dräger Pir 7000 / Dräger Pir 7200; Dependance Of Calibration On Ambient Pressure - Dräger PIR 7000 Technical Handbook

Maintenance

Calibration

General

The gas transmitter has been factory-calibrated for methane, propane and ethylene (Dräger
PIR 7000 type 334) or methane and propane (Dräger PIR 7000 type 340) or carbon dioxide
(Dräger PIR 7200). It can be useful and necessary to renew or to check the calibration.
Observe national instructions and regulations, if applicable.
The gas transmitter requires a 2-point calibration: A zero-point calibration and a sensitivity
calibration at a suitable point within the measuring range (span calibration).
Always use calibration adapter PIR 7000 (part no. 68 11 610).
Zero gas free of measurement gas must basically be used for zero-point calibration. Dräger
Safety recommends to use clean compressed air or nitrogen.
If calibration is performed on the Dräger PIR 7000 gas transmitter using ambient air (fresh
gas calibration), make sure that no measured gas and no other hydrocarbons are in the
ambient air during calibration.
The zero-point calibration of the Dräger PIR 7200 gas transmitter must always be carried out
using nitrogen or synthetic compressed air (without carbon dioxide traces, i.e. with a
percentage of <0.001 % vol.).
The sensitivity calibration can be performed with gas from the device's internal gas library. In
an ideal state of affairs (which is however not essential), the calibration gas is identical with
the measured gas.
The gas transmitter is factory-preset to a calibration gas concentration for the span
calibration, see table on page 63. Perform the span calibration with this concentration;
otherwise, the risk of getting higher measuring errors during operation increases. The
calibration gas concentration can also be found on the configuration label and – if
necessary – the calibration value can be changed using the Dräger CC-Vision GDS
Software, see "Calibration using the Dräger CC-Vision GDS Software" or the Instructions
for Use of the Dräger CC-Vision GDS.
Possible Ways of Calibration for the Dräger PIR 7000 / Dräger PIR 7200
— Locally using the magnetic wand (part no. 45 43 428).
— Using the Dräger CC-Vision GDS Software.
®
— Using a HART handheld terminal (only devices with integrated HART

Dependance of Calibration on Ambient Pressure

The gas transmitter provides a measurement signal which depends on the partial pressure of
the gas component to be measured. Variations of atmospheric pressure, or of absolute
pressure in dependance of the altitude of the site of operation, cause variations of the partial
pressure.
Dräger PIR 7000 [%LEL]
The influence is:
Dräger PIR 7200 [% vol.]
P = current pressure in the measuring cuvette
i
54
CAUTION
Measured value [%LEL]
=
Measured value [% vol.]
®
interface).
P
i
X
1013 mbar