JF-1A Conductivity Sensor
A440-009
Page 26 of 56
FEBRUARY 2009
Box Car Average N
63% Response
Seconds
90% Response Seconds
1
1
1
2
3
7
3 *
6
11
4
7
17
5
9
21
6
11
26
7
13
30
8
15
36
9
17
40
10
19
44
•
N= 3 is Factory Default
Window (Data De-Spike filter):
Window Filter “W”. This Window filter can be used with or without N set.
Essentially the window filter limits the rate at which the JF-1A sensor output can
change from scan to scan. W has units pS/cm/scan, and can be set from 0 –
999. W is an effective tool to reduce data output spikes in installations where
sudden physical changes of the system may cause data spikes. In essence if
the raw conductivity value changes greater more than the current setting of W,
the output change is limited to W. If N is also set then the output change is
limited to W * 1/N.
The mathematical formula for Window Filter has the form:
Test = Raw old – Raw new
If Test > W then Limit Change to W
De-spiked Output = 1/n * W + n-1/n * old reading
