GMI GT series User Manual

12-1
ALARMS
12.1 GAS ALARMS
The following gas alarms are available according to gas type and are
programmable according to application and / or customer preference.
(See Tables 12.1 and 12.2).
12.2 FLAMMABLE (LEL) ALARMS
Up to three (3) instantaneous alarm levels are programmable. All
three are rising alarms, i.e. if the concentration is above the specic
alarm level, the alarm is triggered.
12.3 OXYGEN (O
2
) ALARMS
Up to three (3) instantaneous alarm levels are programmable, one (1)
rising and two (2) falling (to trigger alarms in O
2
decient scenarios).
12.4 TOXIC GAS (e.g. CO) ALARMS
When operating normally, the instrument records minimum and
maximum readings for each gas. It also calculates the Short Term
Exposure Limit (STEL) and Long Term Exposure Limit (LTEL), known
as Time Weighed Average (TWA) readings, for each toxic gas range
as appropriate. Up to two (2) instantaneous rising and two (2) TWA
alarms are programmable for each toxic range tted to the instrument.
Note: A Time Weighted Average (TWA) value is the mean average
gas level over a specic period. The STEL is 15 minutes
and the LTEL is 8 hours. In accordance with legislation, this
requires the time weighted averages to be averaged over
a full period whether the instrument is ON or OFF. Such
12

GMI GT series Specifications

General

Brand	GMI
Model	GT series
Category	Measuring Instruments
Language	English