Intended Use; Limitations On The Intended Use; Installation & Commissioning; Sensing Head Assembly - Dräger Polytron SE Ex PR M1 DQ Notice D'utilisation

Installation & commissioning
Name Housing
type
Polytron SE Ex PR M1 M1
DQ
Polytron SE Ex PR M2 M2
DQ
Polytron SE Ex HT M DQ HT
Polytron SE Ex PR NPT1 NPT1
DQ
Polytron SE Ex LC M1 DD M1
Polytron SE Ex LC M2 DD M2
1) Temperature range up to 150 °C
3.2

Intended use

The sensing heads Polytron SE Ex PR M1/2 DQ and SE Ex PR NPT1 DQ as
well as SE Ex HT M DQ and SE Ex LC M1/2 DD are intended for fixed-location,
continuous monitoring of combustible gas/air and vapour/air mixtures under the
Lower Explosive Limit (LEL) or below 10 % of the LEL in atmospheric
conditions.
All sensing heads contain sensors with the pressure-resistant enclosure with
"db" type of protection, or housing with "tb" type of protection.
The DrägerSensor PR M DD, HT M DD and PR NPT DD sensors will be
replaced by the DrägerSensor PR M DQ, HT M DQ and PR NPT DQ sensors.
The DD sensors can still be used with the sensing heads.
3.3

Limitations on the intended use

The sensing heads are not approved for use with an increased oxygen content
(>21 Vol% O ). None of the sensing heads and sensors given in this document
2
is certified and approved for operation in oxygen enriched atmospheres.
DrägerSen- Measuring
sor range
PR M DQ 0–100 %LEL
PR M DQ 0–100 %LEL
HT M DQ
1)
0–100 %LEL
PR NPT DQ 0–100 %LEL
LC M 0–10 %LEL
LC M 0–10 %LEL
4 Installation & commissioning
4.1

Sensing head assembly

4.1.1

Assembling the sensing head

Comply with regulations on electrical equipment in explosion-hazard areas and
with approval conditions!
The approval marking is located on the sensing head housing lid in each
case. During assembly, ensure that the lid and bottom section remain allocated
to one another.
Orientation
Although the Polytron SE Ex PR M1/2 DQ and SE Ex PR NPT1 DQ sensing
heads, as well as the SE Ex HT M DQ, can be operated in any orientation, they
should ideally be installed with the sensor gas inlet area pointing downwards.
For installation in the cover area, mounting brackets should therefore be used.
The Polytron SE Ex LC M1/2 DD sensing heads should always be fitted with the
gas inlet area of the sensor pointing downwards.
– Install the sensing head at a location with minimal vibration and maximum
temperature stability (no direct sunlight) in the vicinity of a possible leak.
– Consider the full scope of environmental conditions affecting the sensing
head. Avoid external influences such as splashing water, oil, corrosive
aerosols (salt mist), etc. and the possibility of mechanical damage.
– The gas inlet area of the sensor must be protected against water, dust and
mechanical damage, and kept free of contamination at all times. In
particular, paint must not be allowed to seal up the gas inlet opening during
painting work.
– If the sensing head is being used to detect combustible vapours, the ground
clearance should be kept as low as possible, whilst still providing access for
calibration work. Where appropriate, the sensing head should be installed in
a removable position.
Mounting the sensing heads
Polytron SE Ex PR M1/M2 DQ
Polytron SE Ex LC M1/M2 DD
4 screws (4 mm diameter), through
the housing