The average current measured by PPK2 is inaccurate, with a deviation of approximately 8%.

[fae2]

All of the following used the same power supply to power our development board and measure the current of the development board:
The PPK2 I purchased measured an average current of 1.27mA. The results were consistent when the program selected 1s, 3s, and 10s.
Using another PPK2 of the same model, the average current was measured to be 1.24mA. The results were consistent when the program selected 1s, 3s, and 10s.
Using a high-precision ammeter, the current was measured to be 1.18mA.
1. The test result of the PPK2 I purchased differs significantly from that of the high-precision ammeter, approximately 8%. This has a considerable impact on our daily tests. Could you please explain what the reason is?
2. Is the measurement accuracy of PPK2 inferior to that of ordinary multimeters and high-precision ammeters?

[Simon D-M]

Hi,

The accuracy you are measuring is inside the expected range (link). for the "500 µA–5 mA" range, we have a typical +/-10% accuracy on the average value.

1. The test result of the PPK2 I purchased differs significantly from that of the high-precision ammeter, approximately 8%. This has a considerable impact on our daily tests. Could you please explain what the reason is?

This device has not been made for absolute accuracy, it has been made to give a way to monitor very small current. It is very useful for current debugging an application and also to make good estimations on current consumptions.

2. Is the measurement accuracy of PPK2 inferior to that of ordinary multimeters and high-precision ammeters?

Yes, it is worse than some ordinary multimeter in certain range. However, it can measure current that are magnitude lower than most multimeters. It also has a desktop app that logs all the current consumption and help with estimating battery life, current debugging, and so on. Thus, cannot really be compared to a normal multimeter.

Concerning, the high-precision ammeter, of course it will be better at measuring. But it will also probably be orders of magnitude more expensive than our PPK2. So it also cannot really be compared.

Best regards,

Simon D-M  

[PaKa]

One thing to check for the desktop multimeter, is it averaging over longer time? There are a lot of short pulses on the current flow with the Nordic devices and without this longer filtering time (we use 1s with Agilent meters) then you more or less always get incorrect readings.

But as Simon says, this is high compared to the spec but inside. Normally we see less than a couple of percents off.