SA9603C

sames

11/18

8.

Calibration

For calibration of the SA9603C, the following procedure is recommended:

a. Establish the calibration factor for active energy (Ka) at power factor (PF)

close to 1.

Active (Measured) = register_value (Active) * Ka.

1

b. The factor for reactive (Kr) is typically Ka * PI/2.

For higher accuracy of Kr, establish Kr at PF close to 0.

Reactive (Measured) = register_value (Reactive) * Kr

2

c. At PF close to 1, establish error for reactive (Er)

Er = (Reactive (Measured) - Reactive (True)) / Active (Measured)

3

Reactive (Corrected) = Reactive (Measured) - Er * Active (Measured)

3b

Measurement

Having determined the scaling factors (Ka & Kr) and error correction constant (Er)

the measurement cycle consists of the following steps:

Step 1

Read active register

Step 2

Calculate Active (Measured) as per 1

Active energy

Step 3

Read reactive register

Step 4

Calculate Reactive (Measured) as per 2

Step 5

Perform error correction

Calculate Reactive (Corrected) as per 3b

Reactive energy

The above five steps must be performed for each measurement cycle.

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