Configuration; Selecting A Measured Gas; Loading Additional Measured Gases (Dräger Pir 7000 Only); Selection And Modification Of Lel (Dräger Pir 7000 Only) - Dräger PIR 7000 Technical Handbook

Operational Characteristics
Configuration

Selecting a Measured Gas

The Dräger PIR 7000 / Dräger PIR 7200 gas transmitter supports the linearised and
temperature compensated display of several gases and vapours.
Before commissioning, the measured gas suitable for the application can be selected from
the gas library included in the device software. The configuration of the measured gas as well
as the measurement unit and measuring range, in which the gas concentration is indicated,
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can be changed using the Dräger CC-Vision GDS Software as well as a HART DD/DTM
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based software or a HART handheld terminal. The procedure is described in the
corresponding Instructions for Use.
Loading Additional Measured Gases (Dräger PIR 7000 only)
The Dräger PIR 7000 gas library is prepared for up to ten additional measured gases. The
currently available selection of gases and vapours supported by the gas transmitter will be
supplied by Dräger Safety on request. The Dräger Safety service department can perform the
upload of additional measured gases.
Selection and Modification of LEL (Dräger PIR 7000 only)
Regionally different conversion factors may apply for the display of measured concentrations
in percent of the lower explosion limit LEL. The Dräger PIR 7000 gas transmitter allows you to
select one of three LEL categories which basically correspond with common explosion limits
in the USA (acc. to NIOSH), Europe (acc. to IEC 60079-20) and Germany (acc. to Brandes /
Möller – Sicherheitstechnische Kenngrößen, Band 1: Brennbare Flüssigkeiten und Gase).
The stored values are specified in the tables "Cross-Sensitivities" on page 75 to page 76.
In addition, individual conversion factors can be set based on the stored value of the selected
LEL category. In this case, the range is always limited to 75 % to 125 % of the value of the
selected LEL category.

Calibration Gas

For many gases and vapours, the calibration with the target substance is a major problem
because either a suitable calibration gas is not available, or because the vapour pressure of
the liquid is too low at the ambient temperature, or because the handling of a calibration
chamber in the field is problematic. A calibration using a substitute gas is always a tedious
process which can end with a significant linearity error.
The Dräger PIR 7000 gas transmitter allows a free selection of substitute gas calibrations with
any commercially available test gas (e. g. methane or propane) without further conversion,
provided this gas is listed in the gas library of the gas transmitter.
A calibration gas deviating from the selected measured gas is set for the calibration of
sensitivity (span). In calibration mode, the gas transmitter is first calibrated to the actual,
currently configured test gas concentration. Calibration data are then automatically converted
to the measured gas setting upon exiting the calibration mode. The specified measurement
accuracy for the selected measured gas is ensured by means of the specific gas parameters
stored in the gas transmitter.
All settings described above can be carried out using Dräger CC-Vision GDS Software as
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well as using HART DD/DTM based software or a HART handheld terminal.
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