Honeywell Touchpoint Pro Technical Handbook page 101

10.2.1 TWA Start of First Shift Time
This setting is not used by the LTEL calculation and does not need to be changed.
10.2.2 LTEL Algorithm
The CCB will calculate the moving average of the LTEL for an 8-hour time interval.
Where:

LTEL = Long Term Exposure Limit TWA

TEN_MIN_TWA1 = 1st Ten-Minute TWA

TEN_MIN_TWA2 = 2nd Ten-Minute TWA

TEN_MIN_TWAN = Nth Ten-Minute TWA

LTELN = Number of Ten-Minute TWA Samples received in 8 hours
CCB will use the Ten-Minute TWA for LTEL moving average calculations:
Where:

TEN_MIN _TWA = Ten-Minute TWA

HM_TWA1 = 1st Half-Minute TWA

HM_TWA2 = 2nd Half-Minute TWA

HM_TWAN = Nth Half-Minute TWA
The CCB will add the 'Half-Minute TWA' samples received in 10 minutes and then divide it by the TEN_MINN to calculate
the 'Ten-Minute TWA'.
Every half minute the CCB updates LTEL TWA by discarding HM_TWA1 and adding the latest HM_TWAN.
Every 10 minutes the CCB recalculates the LTEL TEN_MIN_TWA and divides it by 'TEN_MINN' to give a new reading.
Part. No. 2400M2501_6
CONFIGURATION
LTEL = (TEN_MIN_TWA1 + TEN_MIN_TWA2 + → + TEN_MIN_TWAN) / LTELN
TEN_MIN_TWA = (HM_TWA1+ HM_TWA2 → + HM_TWAN) / TEN_MINN
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Touchpoint Pro
Technical Handbook