Threshold Alarm Hysteresis - Honeywell touchpoint Pro Operating Instructions Manual

MAN0923_Issue 3_04/15
15. Appendix 2 - Configurable
Parameter Reference Guide

15.1.10 Threshold Alarm Hysteresis

Access Level: Engineer
Parameter Name Default Setting
Threshold Alarm 2 %FSD
Hysteresis
15.1.11 Short Term Exposure Limit (STEL) Alarm Settings
Caution: In some countries, the use of STEL and LTEL alarms with fixed gas detection equipment is
not recommended. Refer to local and national regulations.
Note: The Short Term Exposure Limit (STEL) calculation is a moving time-weighted average (TWA) gas
reading over a given time interval (STEL Time Interval). The STEL alarm is set if the result exceeds the
configured STEL Alarm Level. The STEL sample rate is 4 Hz, and the STEL reading is updated every 30 s.
STEL
where
STEL
HM_TWA1
HM_TWA2
HM_TWAN
STELN
Access Level: Engineer
Parameter Name
STEL Alarm Enable
STEL Alarm Level
STEL Alarm Latch
STEL Time Interval
15.1.12 Long Term Exposure Limit (LTEL) Alarm Settings
Caution: The Touchpoint Pro LTEL calculation assumes an 8 hour working period. In some countries,
the use of STEL and LTEL alarms with fixed gas detection equipment is not recommended. Refer to
local and national regulations.
Note: The Long Term Exposure Limit (LTEL) calculation is a moving time-weighted average (TWA) over an 8
hour time interval. The sample interval is 30 s, and the LTEL reading is updated every 10 minutes.
Value Range
0.0 to 10.0 %FSD
= (HM_TWA1 + HM_TWA2 + HM_TWA3 ..........+ HM_TWAN ) / STELN
= Short Term Exposure Limit TWA
= 1st Half Minute TWA
= 2nd Half Minute TWA
= Nth Half Minute TWA
= Number of Half Minute TWA Samples received in STEL interval
Default Setting
Disabled
20 %FSD
Latching
10 min.
Comment
The hysteresis value will be applied to a channel coming out
of an alarm condition, e.g. if the alarm level is 20 %FSD, and
hysteresis is set to 2 %, the alarm will not be cancelled until
the reading has dropped below 18 %FSD.
Value Range
Enabled / Disabled
According to sensor range
Latching / Non-Latching
5, 10, 15, 20, 30, 40 and 60 min.
195
Touchpoint Pro
Operating Instructions