Measuring mode
The gas transmitter generates a 4 to 20 mA signal, proportional to the measured gas
concentration and linear according to the 0 to 100 % full scale value, if the gas transmitter is
configured for analogue signal transmission.
Current
Meaning
4 mA
zero-point
20 mA
full-scale deflection
Special Conditions
<1.2 mA
fault, configurable
2 mA
beam block warning, configurable
3 mA
maintenance signal, configurable
3.8 mA ... 4 mA
deviation below zero point
20 mA ... 20.5 mA
full-scale deflection exceeded (over-range)
>21 mA
Device Error
Fault messages are issued with a higher priority than warning messages. Warning messages
are issued with a higher priority than measured values.
It is a requirement of EN 50271 that "the maximum time for 4 consecutive updates of the
output signals" must not exceed the measured value response time t0...90 of the
gas transmitter. For the Dräger PIR 7000 / Dräger PIR 7200, the measured value is
calculated every approx. 2 s (repeatability in "normal response mode") or every approx. 0.5 s
(repeatability in "fast response mode"), and the current of the analogue 4 to 20 mA output
signal is updated every approx. 100 ms.
Maintenance
The gas transmitter is maintained either using the Magnetic Wand (part no. 45 44 101, calibration
only) or using the Remote Access Box Dräger RAB 7000 (part no. 68 12 830, calibration and
configuration of the parameters that may need to be changed for calibration only) or using a
computer running Dräger PolySoft software or using a manual control unit made by HART
All statuses (e.g. manual setting of the analogue output signal) that temporarily interrupt measuring
mode of the gas transmitter are indicated by the status lights (green on or yellow flashing).
Maintenance intervals
Observe EN 60079-29-2 and respective national regulations.
While commissioning
Check the function of the yellow and green status lights while the automatic self-test
is running.
Check zero-point calibration.
Check the current interface and if required also the HART communication.
At regular intervals, which are to be determined by the person responsible for the gas
detection system – recommendation, 6 months
Check the zero-point and the span calibration.
Check signal transmission to central unit and alarm activation.
It is possible to extend the calibration interval beyond the recommended 6 months under the
following conditions: Following a usage period of max. 6 months, a check must be made of
whether the gas feed to the measurement cuvette can be blocked e.g. by dust, oil etc. in the
present application. If there is no possibility of the function being restricted by such effects,
the calibration interval can be extended – we recommend a maximum of 24 months.
1) For applications in line with PFG 16 G 003 X, the calibration interval must not exceed 6 months.
NOTICE
1)
:
Yearly
Inspection by competent personnel. The inspection intervals are to be individually determined
with regard to safety regulations, process control conditions and device-related requirements.
Checking the alarm triggering. The alarm triggering function should be tested either by
applying test gas or by manually setting the 4 to 20 mA signal (using a computer and the
Dräger PolySoft software). The concentration of test gas or the 4 to 20 mA signal set must
be sufficiently high to trigger the main alarm.
Check the measuring cuvette of the gas transmitter and clean if required
To avoid false alarms during inspection, set the analogue output signal to maintenance
signal or ensure that the alarm activation at the central device is locked.
Remove the splash guard and, when required, any additional accessories from the gas
transmitter.
Examine the air inlet and air outlet openings for contamination and damage.
Examine the windows, mirrors and additional accessories for contamination, clean with
water or alcohol and dry using cotton wool or a cloth. Do not scratch the mirrors or windows!
Attach the splash guard and any other accessories, as appropriate, to the gas transmitter.
Reactivate the analogue output signal if it has been set to maintenance signal. Unlock the
alarm activation at the central device once more.
Calibration
The gas transmitter is operated either using the Magnetic Wand (part no. 45 44 101) or using
the Remote Access Box Dräger RAB 7000 (part no. 68 12 830) or using a computer running
Dräger PolySoft software or using a manual controller made by HART
purposes, test gases can be applied using the calibration adapter PIR 7000 (part no. 68 11 610),
the Flowcell PIR 7000 / 7200 (part no. 68 11 490 / 68 11 910), the Flowcell PIR 7000 Duct
(part no. 68 11 945), the process adapter PIR 7000 (part no. 68 11 915), the process cuvette
PIR 7000 (part no. 68 11 415) or the process cuvette PIR 7000 SGR (part no. 68 13 219).
Observe the installation instructions in the accompanying IFUs of the respective accessories.
Always calibrate zero-point first, then calibrate span. A span calibration can only be per-
formed within 24 hours after zero point calibration. Always use the calibration gas specified
®
.
on the gas transmitter for span calibration.
Handling the magnetic wand:
The gas transmitter contains two contact locations marked by » 0 «
and » S « on the housing. To calibrate, place the magnetic wand on
the contact points as shown on the following schematic.
After the respective specified timeout values run out, the process is automatically terminated
without saving the values, and the gas transmitter returns to normal operation.
®
. For calibration
NOTICE
S
0
NOTICE
25