# Calibration Recommendation

URL: https://irs.systems/en/docs/cmm-iii/calibration-recommendation

IRS recommends a recalibration within 2 years.

The calibration should be performed at multiple calibration points for all 7 ranges. IRS recommends measuring at least the following currents:

| Range | Calibration points |
| --- | --- |
| 100 µA | 20 µA, 40 µA, 60 µA, 80 µA, 100 µA |
| 1 mA | 0.2 mA, 0.4 mA, 0.6 mA, 0.8 mA, 1 mA |
| 10 mA | 2 mA, 4 mA, 6 mA, 8 mA, 10 mA |
| 100 mA | 20 mA, 40 mA, 60 mA, 80 mA, 100 mA |
| 1 A | 0.2 A, 0.4 A, 0.6 A, 0.8 A, 1 A |
| 10 A | 2 A, 4 A, 6 A, 8 A, 10 A |
| 100 A | 20 A, 40 A, 60 A, 80 A, 100 A |

CMM values should be captured with the RS232 or ISO-TP function **`GLVAL`**. This function returns the value averaged since last read.

Before capturing a valid value, enable the calibration current, perform a dummy read and wait 100 ms.

The fluctuations of the power source used should not exceed 0.1% of the nominal value.