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7-3 Calculating 16 Point K Factors
7-3 Calculating 16 Point K Factors
Units equipped with the 16 Point option allow the
user to enter in from 3 to 16 different frequency
points (inputs per second) and assign different K
Factor dividers from 0.00011 to 999999 for each
of these frequencies. The 16 Point unit deter-
mines the incoming frequency and calculates a K
Factor line slope from the two closest data points
that had been entered. The specifi c K Factor is
then proportionally interpolated using 8 position
fl oating math. This K Factor is applied to all in-
puts until the next frequency calculation, usually 1
second later. If a 0 frequency is entered into point
1, the point 1 K factor will be applied to all inputs
received before the fi rst frequency calculation.
In order to keep track of data, each Frequency /
K Factor data entry is assigned a point number.
Any point number may be selected to view and /
or change the Frequency / K Factor data as long
as the frequencies of the ascending point num-
bers are also entered in ascending frequencies.
7-3.1 Some Notes on 16 Point Setup
1)
The unit will not accept a K Factor of (0) zero.
If a zero is entered the unit automatically puts
a (1) one in its place. Division by zero is not al-
lowed.
2)
Point 01 will be the low shut-off frequency.
Below this frequency no rate will be displayed nor
count recorded. Point 01 should be assigned a
frequency of (0) zero with a K Factor for lowest
fl ow especially if very slow fl ow is to be counted.
3)
The entry of a frequency of (0) zero for Point
03 or above will tell the unit to continue the K Fac-
tor slope line calculated from the two previous
Frequency / K Factor points and ignore any higher
point data. If a fi xed K Factor is desired, assign
the same K Factor to two ascending frequency
points and enter a frequency of (0) zero in the
next higher point entry.
4)
Extrapolated K Factors are always positive
numbers. Make sure that the last two points do
not project the K Factor slope towards zero.
5)
The dummy decimal point is still set up with
DEC LOC menu under DEV TYP. However,
the auto-ranging decimal point in the rate display
will be shifted to the left as the dummy decimal
is shifted to the left. This is so that the rate dis-
play will be as same as the count. For example:
The input pulses are coming in at 100 pulses per
minute. The decimal point is set at (1) one (DEC
LO.C). At the end of one minute the count will
read 10.0. During the minute the rate will read
10.0 while it would show 100.0 if no decimal point
were added.
7-3.2 Test Mode Operation and K Factor Calcula-
tion
A special TEST mode can be accessed through
the 16 Point setup menu. This is used to help set
the points and K Factors as well as calibration of
the metering device. If TEST is selected, the K
Factor is set to (1) one for all frequencies. Thus,
the totalizer will accumulate one count for each in-
coming pulse. Below are steps for calculating the
K Factors with pulsing devices or analog transmit-
ters.
1)
Set the 16 Point unit to TEST and press ENT
on POINT 00 to go to the run mode.
2)
At the lowest desired fl ow rate, reset the coun-
ter and let the unit count the incoming signal while
the rate displayed is recorded.
3)
Interrupt the input signal when the known
tested amount has gone through the metering de-
vice. Switch to count display and read the number
of counts that came in from the known volume as
displayed on the unit. Divide the counts by the
volume that passed through the meter to deter-
mine the number of counts for 1 unit of measure,
gallon, cubic feet, etc.
4)
Record this frequency and K Factor for later
entry into Point 01 or Point 02. (See 7-3.1 Note 2
to determine if the data should be entered in point
1 or 2)
5)
Assign ascending point numbers to corre-
sponding ascending frequencies when recording
Frequency / K Factor data. Repeat process until
desired number of points are set up.
