Guru
Joined: 11/02/2018
Location: AustraliaPosts: 3375
| Posted: 06:42am 07 Jul 2025 |
If you have the panels connected to a switch-mode MMPT or charge controller the high frequency may be affecting the accuracy of the meter.
An old analogue Hot Wire ammeter will give true RMS from DC-to-Daylight.
It uses a thermocouple connected to a short piece of resistance wire.
Slow response and +/- 3% of full scale are its limitations.