Liquid Controls AN25 - Manual (Page 6)

Sponsler Co., Inc. AN25 Totalizer/Rate Indicator pg. 6 DOC#: MN-AN25
CALIBRATION
Sensitivity
The sensitivity adjust R6 is located on the Power Supply and Input Amplifier P.C.B. The amplitude of the signal
generated by the turbine is proportional to the rate of flow, therefore, sensitivity should be adjusted at the lowest
usable flow rate. Rotate R6 completely counter-clockwise, then slowly rotate R6 clockwise until the display correctly
responds, then increase R6 slightly clockwise.
Calibration Factor for Total & Rate
The calibration factor is derived from the turbines K-Factor (Pulses per gallon or other desired engineering unit).
The K-Factor is listed on the calibration data sheet for the specific turbine being used.
C.F. =
Engineering Units
K-Factor
Example # 1: K-Factor = 250 Pulses per gallon
Desired Engineering Units = gallons
C.F. = 1/250 = .00400
On the factoring P.C.B.
Set S6 #3 ‘ON’ (
↓ Position) for ÷ 100 (Moves decimal point right 2 places)
Set S2 @ 4, S3, S4, S5 @ 0 (Enters .4000)
Set S1 in ‘0’ Position (0.4000)
The electronic accuracy can be verified by injecting a stable frequency @ TB1-10, 11 and
incorporating the following formulas:
Total =
F x T x C.F.
D
Rate =
F x C.F. x 60
D
Where F = Frequency in Hz
T = Time (Duration) of test in seconds
C.F. = Calibration Factor as entered in S1-S5
D = Divisor as entered in S6
Example #2:
F = 500 Hz T = 2 min (120 sec) C.F. = .4000 D = 100
Total = 500 x 120 x 4000
100
= 60,000 x 4000
100
= 24000/100 = 240 in 2 minutes
Rate = 500 x .4000 x 60
100
= 120 per minute
(Rate is per minute)