Intended Use
Intended Use
The Dräger Polytron Pulsar 2 Open Path Gas Detector is intended for stationary,
continuous monitoring of hydrocarbon gases or vapours that may present and
explosion hazard.
Explosion protection approvals
The explosion-protection approvals are valid for use of the device in gas/vapour-
air mixture of combustible gases and vapours under atmospheric conditions. The
explosion-protection approvals are not valid for use in oxygen enriched atmospheres.
In case of unauthorized opening of the enclosure, the explosion-protection approval
is voided.
NOTE: The Dräger Polytron Pulsar 2 Open path Gas Detector is one of the
family of detectors certified under the designation GD8. All certificates will
refer to the GD8.
Parts Supplied
1.
The Dräger Polytron Pulsar 2 Open Path Gas Detector comes in two parts,
a transmitter and a receiver; each supplied with an ABS moulded cover.
Additionally the detector is supplied with either:
— Flying leads and Ex e junction boxes.
— Ex d certified plugs and sockets.
2.
An optical attenuator for use on beam paths between 4 and 16 meters, NOTE
this is only supplied with 4-60m transmitters.
3.
An installation sheet and a quick start guide are supplied with the detector.
Installation/operation manuals are also available through local distributors or
by contacting Dräger UK Ltd.
4.
You will also require a commissioning kit which is ordered separately and
includes:
— Hand Held terminal (HHT)
— 4mm Allen key
— Test Sheets
— HHT PC software
— PC Cable
Installing
Only trained service personnel (e.g. Dräger service personnel) may install the gas
detector under observation of the regulations applicable at the respective location.
Choosing the path of the beam and Mechanical Installation
1.
The siting of an open path gas detector is often not as critical as a point
detector, since the released gas only has to find its way into some portion of
the beam instead of to a particular point. However, siting is still an important
consideration. Guidance for siting is contained in EN 60079-29-2.
2.
Dräger Polytron Pulsar 2 Open Path Gas Detector is immune to sunlight so
there is no need to take account of the sun position when siting detectors.
3.
The density of the gas to be detected has to be considered. Methane is lighter
than air and may be expected to rise, unless released at a low temperature
or in a mixture with a heavier gas like carbon dioxide. Likewise, heavier
hydrocarbons may be expected to fall. However such simple considerations
as buoyancy may not be a reliable indicator of gas movement in practical
situations. Gas leaking from high-pressure systems entrains with it a much
larger volume of ambient air, forming a mixture that may be flammable and
almost neutrally buoyant. In these circumstances, it is the natural air currents
or forced ventilation that control the motion of the plume or cloud. Where
air movements are unpredictable it may be necessary to use separate beam
paths to cover different possibilities.
4.
The distance between the transmitter and receiver should agree with the
model selected (i.e. 4-60m, 30-120m or 100-200m). Note that the optical
attenuator should be fitted below 16 metres.
5.
The beam path and immediate surround should be kept free of obstructions
that might hinder the free movement of air in the protected area or block the
infrared beam. A clear path of 25cm diameter or greater is recommended.
For maximum availability it is also recommended to avoid the following:
— Smoke stacks, chimneys and exhausts.
— Steam vents and plumes.
