I'm in the market for a clamp ammeter. Looks like measurement error at low current is between 0.05A and 0.10A
Some meters have 0.1A resolution and 10x the error of those with 0.01A resolution, pretty much unusable for PV strings.
Klein CL900:
Has inrush feature.
Clamp DC amps, 2000A 1A resolution, 600A 0.1A resolution, accuracy +/-(2% + 5 digits)
Presumably not really "digits", but counts in the last digit. 5 x 0.1A = 0.5A error. 2% of reading? Or 2% of full scale? Either 1.2A error if full scale, or say 0.2A if reading a 10A PV string. 0.5A + 0.7A = 0.9A, 9% error reading my PV string.
If 1A, 2% = 0.02A, 5 counts = 0.5A, error is 0.52A or 52%
Harbor Freight Ames 1000A clamp meter:
Has inrush feature.
1000A, 600A, 60A scales. 2% + 8 counts. That's 2% of 10A = 0.2A + 8 x 0.01A = 0.28A, 2.8% error reading PV string, not as bad.
If current is just 1A, 2% = 0.02A, 8 counts is 0.08A, error is 0.1A or 10%.
Fluke 325:
Designed to verify the presence of load current, AC voltage & circuits & switches, the Fluke 325 Clamp Multimeter offers big features in a small form.
www.fluke.com
400A, 40A. 2% + 5 counts. 2% of 10A = 0.2A, 5 x 0.01A = 0.5A, 0.25A error or 2.5%
If 1A, 0.02A + 5 x 0.01A = 0.07A, 7%
Having 0.01A resolution and several counts error pushes error toward 10% for lower current around 1A from a string.
My primary application is checking parallel strings, see how they're performing.
Might be nice to handle 600A not just 400A, measure battery current with full-load 24kW at 48V. Surge would be double that.
Not clear these meters have a DC surge feature; mention is either AC or 40 to 400 Hz.
I could measure current to just one inverter, then about 125A full load, double that for up to 3 seconds.