Honeywell 04230-A-1001 - Abbreviations

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MAN0530 Issue 15 - 07/17 Searchline Excel
2104M0506
Generally, gas readings of LEL.m (Lower Explosive Limit metres) are used. LEL.m is
calculated by multiplying the size of a gas cloud by its concentration.
An open path alarm set at 1 LEL.m would be triggered by any of the situations shown below:
100% LEL
1m
2m
10m
ESC
Calibrator
Type SHC1
ESC
Calibrator
Type SHC1
50% LEL
ESC
Calibrator
Type SHC1
ESC
Calibrator
Type SHC1
10% LEL
ESC
Calibrator
Type SHC1
ESC
Calibrator
Type SHC1
LEL.mmonitoringisparticularlybenecialwhiletheExcelgasdetectorisprotectingtheperimeter
of a plant or process, often reducing the quantity of point detectors required. The open path
LEL.m system has the ability to detect leaks that point detectors may miss due to prevailing
or changing wind directions, and can provide early warning of a dilute gas cloud when point
detectors may not register any gas presence.
Todecideonalarmsetpoints,itisrecommendedthattheuserrstlydeterminethesizeofgas
cloud that they wish to protect against, then set the alarm point to a fraction not greater than 60%
ofthatcloudsize.Forexample,toprotectagainsta5mcloud,setthealarmpoint≤3LELm.
B.3 ABBREVIATIONS
ATEX European Hazadous Area Approval
CSA Canadian Standards Association
DNV Det Norske Veritas
DSP Digital Signal Processor
EMC Electro-Magnetic Compatibility
FM Factory Mutual
IAA Instrument Assisted Alignment
IECEx International Hazadous Area Approval
APPENDIX B - GLOSSARY