Badger Meter Model IOG User Manual

Page 21

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NOTE:

N

If the number of linear points is set to 1 the ER-500 assumes the user is entering the maximum frequency and

coefficient Further the meter assumes that the implied first point is at a frequency of 0 (zero) Hz and a coefficient

of 0 (zero)

Frequency

Press the ENTER button once and the first linear point’s frequency input Freq#1 begins to flash Enter the frequency for

the first linear point using

arrow button to increment the numerical values and the ► arrow button to change the

position of the number being entered When the frequency value input is complete, press the ENTER button once again

to change to the coefficient value Coef#1 for the first linear point

Coefficient

The coefficient is the value applied to the nominal K factor to correct it to the exact K factor for that point The coefficient

is calculated by dividing the actual K factor for that point by the average (Nominal) K factor for the flow meter

Linear Coefficient =

Actual K factor

Nominal K factor

Linear coefficient calculation

At the coefficient Coef#1 prompt, enter the coefficient that corresponds to the frequency value previously entered Press

the ENTER button once to move to the scaling point
Continue entering pairs of frequency and coefficient points until all data has been entered Press the ENTER button to

move to the next parameter

NOTE:

N

The frequency values must be entered in ascending order If a lower frequency value is entered after a higher value

the ER-500 flashes Limit followed by the minimum frequency value acceptable to the display

Example:

The following is actual data taken from a 1 inch turbine flow sensor calibrated with water

Unit Under Test (UUT) Calibration Data Table In GPM

Actual

GPM

UUT

Frequency

UUT Actual

K factor

(Hz x 60)

Nominal K

Linear

Coefficient

Raw Error

Hz

Counts/Gallon

GPM

% Rate

50 02

755 900

906 72

49 72

1 0060

0 59

28 12

426 000

908 96

28 02

1 0035

0 35

15 80

240 500

913 29

15 82

0 9987

-0 13

8 88

135 800

917 57

8 93

0 9941

-0 59

4 95

75 100

910 30

4 94

1 0020

0 20

Nominal K (NK)

912 144

Table 3: Sample linearization data

In this example the linear coefficient has already been calculated by the calibration program so all that is required is to enter 5

into the number of linear points Lin Pts parameter and then enter, in order, the five frequency, linear coefficient data pairs

User Manual

Page 21

August 2013

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