Fox Thermal FT3 - Page 68

Pipe Area
Enter the pipe area in square meters or square feet and then press OK (F4). Use square meter for
metric ow unit selection.
F1 F2 F3 F4
Filter Value
The lter value is entered in seconds. The allowable time constant range is 0.8 to 10 seconds. The
lter time interval is proportional to the dampening.
The lter value is also referred to as a dampening factor and is used to quiet the readings. The lter
value is an exponential lter that dampens the noise and is used as follows:
Flow Value = (FA * new value) + (FB * average)
Where FA = lter value, FA + FB is equal to 1.0
A lower lter value will increase dampening of the ow rate and smooth the reading. A lower lter
value will also slow the meter's response. For example, if we enter a lter of 0.8, the weight ratio for
the new average is:
New average = (80% new sample) + (20% last average)
Filter range is 0.01 to 1.0, 0.01 being a high lter value and 1.0 = no lter.
Filter Response (Sec.) 65% of Target
0.9 0.10
0.8 0.15
0.7 0.20
0.6 0.25
0.5 0.30
0.4 0.35
0.3 0.40
0.2 0.60
0.1 1.00
0.05 2.00
0.03 3.00
0.01 10.3
F1 F2 F3 F4
Enter the lter value and then press OK (F4).
A^2 = 0.05672 Ft^2
CHG OK
FILTER = 0.8 sec
CHG OK
Operation | 68
Model FT3
Operation