Installing Transmitter; Mounting; Remark; Pay Attention To Ventilation - Dräger PEX 3000 XTR 0000 Notice D'utilisation

Installing Transmitter

Mounting

Orientation: The measuring signal of the transmitter is depending on the inclination.
The transmitter must be mounted such that the sensor's gas entrance area of the
sensor is pointing downwards. If to be mounted at the ceiling a mounting bracket
must be used.
— Install transmitter in vertical position at a location with little vibration and maxi-
mum temperature stability (no direct sun light) in the vicinity of a possible leak.
— Consider the complete scope of environmental conditions influencing the trans-
mitter Avoid external influences such as splashing water, oil, corrosive aerosols
(salty fogs) etc. and the possibility of mechanical damage.
— Leave at least 30 cm free space beneath the transmitter to provide accessibility
for calibration work.

Remark

Certain substances in the atmosphere to be monitored may impair the sensitivity of
the sensors (Ex-Sensor PR M or Ex-Sensor LC M) installed in the transmitter:
The following substances are known at present:
a) polymerizing substances such as acrylo nitrile, butadiene and styrene,
b) corrosive compounds such as ammonia and halogenated hydrocarbons (relea-
sing halogenes such as bromine, chlorine or fluorine when being oxidised),
c) catalyst poisons such as sulphurous and phosphorous compounds, silicon
compounds, and metal-organic vapours.
The sensors used are based on measuring elements (pellistors) which are poison-
resistant and so have a longer lifetime than conventional sensors if catalyst poisons
occur. However there is still the rule to shorten the test or calibration intervals if cata-
lyst poisons are expected to occur in the atmosphere to be monitored.

Pay attention to ventilation!

— Always arrange sensing head and transmitter in air flow between possible leak or
collection point and possible source of ignition.

Pay attention to the density of gas!

— In case of gases, the density of which is lower than that of air, such as hydrogen,
methane or ammonia the transmitter or sensing head must be located above a
possible leak or at the highest points at which major concentrations of gas may
be found.
— In case of gases and vapours with a density greater than that of air, the sensing
head or transmitter must be installed beneath a possible leak or at the lowest
points at which such gases and vapours may be present.
9023810 - 2nd edition - September 2005
Installing Transmitter
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