MSA Senscient ELDS 1000 series, Operating Manual

Page: 34 / 184

Installation Design & Engineering
34
Senscient ELDS™
Rev 15
GB
Intense Electromagnetic Fields - Senscient ELDS™ OPGDs comply with FM6325 and
EN50270, and as such are well protected from interference by electromagnetic fields. However,
locations in close proximity to radio/radar Transmitters, heavy electrical plant and high voltage
power cables may experience field strengths in excess of those specified in EN50270. Where
possible, such locations should be avoided or units should be installed as far as possible from the
source of the electromagnetic field. Measures including additional screening, filtering and transient
suppression may also be of benefit in such locations.
3.2.4 Beam-path
The Transmitter and Receiver unit lens-windows should face each other directly across the area to
be protected and, depending on the range of the system deployed, should be the following
distance apart:
Senscient ELDS™ Detector Series Type Path length between units
1000 CH
4
5 – 40m, 40 –120m, 120 – 200m
1000 Ethylene 5 – 60m
1000 HCl 5 – 60m
1000 NH
3
5 – 40m, 40 – 120m
1000 CO
2
5 – 40m, 40 – 120m
1000 HF 5 – 60m, 60 – 120m
1000 XD, Cross Duct,
0-10%LFL, 0-25%LFL, 0-50%LFL, 0-100%LFL CH
4
0.5 – 5.0m
2000 CH
4
+ H
2
S 5 – 60m
2000 H
2
S 0 - 100ppm.m 5 – 60m
2000 H
2
S 0 - 250ppm.m 5 – 60m
2000 H
2
S 0 - 500ppm.m 5 – 60m
The beam-path and immediate surrounds 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 beam-path of 20cm
diameter or greater is recommended. In particular, for optimum availability, avoid areas affected by
the following:

Steam vents and plumes

Smoke stacks and chimneys

Walkways and personnel areas

Splash and spray, e.g. from moving equipment, cooling towers, etc.

Parking, loading, cranes, vehicle temporary stops, e.g. bus stops, road junctions, etc.

Vegetation, e.g. shrubs, bushes, branches, etc. - if currently clear, movement due to
weather and future growth or planting must be considered
Where c. and d. cannot be avoided, consider indicating the beam by marking the walkway
or road with paint.