MSA Senscient ELDS 1000 series, Operating Manual

Page: 175 / 184

Appendix G – Measurement Range Guidelines
Senscient ELDS™
Rev 15 175
GB
Guidelines for Open Path Flammable Gas Detectors with 0-5LFL.m Measurement Ranges
(Methane)
In order to comply with earlier requirement specifications based upon NDIR open path gas
detectors, ELDS units can be supplied with a measurement range of 0-5LFL.m. A 0-5LFL.m
(0-500%LFL.m) measurement range is suitable for providing alarms concerning very large
flammable gas releases that will require immediate, emergency action to prevent explosion or fire.
A 0-5LFL.m measurement range is not suitable for providing an early warning about a
flammable gas release, a warning that might allow remedial action to be taken to prevent a
much larger and more dangerous leak from occurring. In order to provide early warnings
about developing flammable gas leaks, lower measurement ranges need to be employed.
ELDS units are available with 0-1LFL.m, 0-10,000ppm.m and 0-1,000ppm.m measurement
ranges. These guidelines recommend the use of a 0-1LFL.m measurement range to
provide alarms about flammable gas hazards that are likely to require immediate,
emergency action; and 0-10,000ppm.m or 0-1,000ppm.m measurement ranges to provide
early warning about a developing flammable gas leak.
Application ► Gas Alarm Threshold
Path Length
5-30 m
0-5LFL.m Methane
A1: 0.75LFL.m
A2: 1.5LFL.m
Path Length
30-60 m
0-5LFL.m Methane
A1: 1.0LFL.m
A2: 2.0LFL.m