Atest Gaz Sigma SmArt, User Manual

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• at other time interval determined on the basis of the survey inspection and changes in
sensitivity during the operation in the plant.
Detectors calibration should be carried out in a laboratory under the fume hood (manufacturer's
recommendation).
When for certain reasons disassembly is not possible, it is permissible to conduct the calibration "in situ",
i. e. without removing the detectors.
A decision in this case belongs to the investor (or their designated person / persons responsible for safety at
the plant) under their responsibility.
After the adjustment process, it is necessary to conduct rechecks of detectors, in order to hedge against
potential errors during the adjustment.
The detector calibration occurs digitally. It involves connecting a PC (e. g. a notebook) to:
detector data bus – in versions with RS-485 – in those versions, a common data bus transfers data
between detectors located in the zone and the central alarm panel always located outside the
explosion hazard area. The service device is connected to the bus already outside the zone,
directly to the detector: when you open the cover – in versions without display (allowed only for
detectors located outside the zone).
The following calibration methods are available:
laboratory method – removal of detectors and securing cables so that they present no danger in
explosive areas, then laboratory calibration in the fume hood (manufacturer's recommendation),
direct method – connect your notebook directly to the detector – calibration "in situ" combined
with opening the housing, permissible only for detectors working outside the zone or detectors in
the zone – after adequate safety precautions – e.g. during a technological standstill, with
explosion hazard control by means of an independent explosion meter and after appropriate
consultation with the owner of the installation,
remote method – connect your notebook to the data bus of the system, outside the potentially
explosive atmosphere. Method recommended by the manufacturer.
The main advantage of this method is that during calibration it is not necessary to perform any
mechanical operations on the detectors (such as the opening of the housing) – with the exception
of screwing the calibration caps and the gas feed. This method also allows the simultaneous
analysis of data by the system manufacturer, provided that a methods of remote data transmission
is applied – the web, modem, etc.
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User's Manual: POD-009-ENG R07