Liquid Controls AN25 - Manual (Page 9)

Sponsler Co., Inc. AN25 Totalizer/Rate Indicator pg. 9 DOC#: MN-AN25
Example #8:
Actual = 50
Displayed = 52
C.F. = .4000
New C.F. = 50/52 x .4000
= .9615 x .4000
= .3846
On the factoring P.C.B.:
Set S2@3, S3@8, S4@4, S5@6
In the above example, .96 denotes that the meter is operating 4% fast. Multiplying by the present C.F.
(.4000) by the Displayed:Actual Ratio (.96) effectively reduces the error by decreasing the C.F. by 4%.
Example #9: Actual = 52
Displayed = 50
C.F. = .4000
New C.F. = 52/50 x .4000
= 1.04 x .4000
= .4160
On the Factoring P.C.B.:
Set S2@4, S3@1, S4@6, S5@0
In the above example, 1.04 denotes that the meter is operating 4% slow. Multiplying the present C.F.
(.4000) by the Displayed:Actual Ratio (1.04) effectively reduces the error by increasing the C.F. 4%.
Rate Display Considerations
The displayed rate is limited to a maximum of 30,000. This characteristic must be considered when determining
the displayed engineering unit. Note that if the desired rate displayed is other than ‘Per Minute’, the calibration
factor is only correct for the rate displayed.
Example #10: A 1” turbine meter has a maximum flow rate of 60 GPM and a K-Factor of 970 pulses per gallon in
Liquid Oxygen. The desired engineering unit is SCFH.
Given: 1 gallon O
2
= 115 SCF
1) Determine maximum flow rate; does it exceed 30,000?
60 GPM x 115 SCF = 6900 SCFM
6900 SCFM x 60 = 414,000 SCFH
414,000 exceeds 30,000. Therefore, direct SCFH units are not permissible and some factor of
SCFH must be determined.
2) Determine what factor of SCFH is permissible –
4140 is the largest SCFH factor under 30,000; 1/100 of the actual SCFH flow rate.
3) Determine the calibration factor for SCFH x 100-
K-Factor = 970 Pulses per gallon
SCF O
2
= 115 per gallon
A) In order to establish x 100 decrease SCF/Gal by a factor of 100 (115/100 = 1.15)
B) In order to establish per hour increase SCF/Gal by a factor of 60 (1.15 x 60 = 69)
C.F. = 69/970
= .07113
On the Factoring P.C.B.:
Set S6 #2 ‘ON’ (
↓ Position) for ÷ 10 (moves decimal point right 1 place)
Set S2@7, S3@1, S4@1, S5@3 (.7113)
Set S1 in ‘0’ Position (.07113)