Liquid Controls AN25 - Manual (Page 12)

Sponsler Co., Inc. AN25 Totalizer/Rate Indicator pg. 12 DOC#: MN-AN25
Calibration of Analog Outputs
REQUIRED EQUIPMENT:
Power Supply 110 VAC or 12-16.5 VDC
2 Digital Multimeters (DMM)
Frequency Generator
Frequency Counter
NOTE: All test equipment power cords should be equipped with 2 prong “cheater” plugs.
a) Connect power supply Positive (HOT) & Negative (NEU) leads to TB1-1,2 respectively.
b) Connect #1 DMM Positive lead TB1-4. Connect #1 DMM Negative lead to 250
Ω resistor; Connect other end
of resistor to TB1-5. Set DMM function to mA DC.
c) Connect #2 DMM Positive & Negative leads to TB1-6, 7 respectively. Set DMM function to Volts DC.
d) Connect frequency generator Positive & Negative leads to TB1-10, 11 respectively. Set output to sinewave
and amplitude to zero.
e) Set “Sensitivity” adjust R1 fully clockwise
f)
Install jumpers at JU1 or JU2 and JU3 or JU4 for desired frequency range.
g) Select desired voltage output level. Install JU5 for 0-10V; omit for 0-5V.
h) Turn Power Supply & Frequency Generator “ON”
i)
Adjust “ZERO” (R25) for 4.00mA #1 DMM indication.
j) Adjust “ZERO” (R40) for .000VDC #2 DMM indication.
k) Adjust signal amplitude of frequency generator to 50mV & frequency to maximum desired point (full scale
frequency)
l) Adjust “SPAN” (R22) for 20.00mA #1 DMM indication.
m) Adjust “SPAN” (R36) for 5.00V or 10.00VDC #2 DMM indication.
n) Reduce signal amplitude of frequency generator to zero. Adjust “ZERO” (R25) for 4.00mA #1 DMM indication,
if necessary. Adjust “ZERO” (R40) for .000VDC #2 DMM indication, if necessary.
o) Adjust signal amplitude of frequency generator to 50mV. Adjust “SPAN” (R22) for 20.00mA #1 DMM
indication, if necessary. Adjust “SPAN” (R36) for 5.00V or 10.00VDC #2 DMM indication, if necessary.
p) Adjust frequency of frequency generator to exactly 50% of maximum frequency point in step K. #1 DMM
should indicate 12.00mA +/- .06mA; #2 DMM should indicate 2.50V or 5.00V +/- .02V.
To check for linearity @ any frequency point:
Voltage output:
F/F Max X Full Scale Output = Volts
Example: Assume maximum frequency point = 2KHz & full scale output = 10v. Check for linearity
@ 750Hz point
750/2000 X 10 = 3.75V #1 DMM should indicate 3.75V +/- .03V
mA output:
(F/F Max X 16) + 4 = mA
Example: Assume maximum frequency point = 2KHz
Check for linearity @ 750Hz point
(750/2000 X16) + 4 = mA
(.375 X 16) + 4 = mA
6 + 4 = 10mA #1 should indicate 10.00mA +/- .06