I may have misinterpreted the description of the Benning that I linked to, which is why I deleted my previous question.
If I managed to understand correctly, then a
The uA measurement does not apply to the clamp meter...
The clamp meter measures with a minimum scale of 10mA.
Yes, it isn't at all clear from the CM 10-PV data sheet. After looking at the user manual it shows the only range that uses the clamp meter is the Amp range. All other measurements including the microamp range require using the probes.
As mentioned above the Fluke 771/772/773 clamp meters have a 10uA resolution but have a limited range to 110mA. They are specialist meters for process control and priced accordingly. The Kyoritsu 2500 is similar with 10uA resolution and max 120mA. I bought my Fluke 771 many (~10) years ago, and apart from my Tek scope it was one of the most expensive pieces of test equipment I owned at the time. I still have it and it still works fine.
The only handheld microamp resolution clamp meters I have come across are for AC leakage measurement, but there may be some specialist ones I haven't seen. I have the UT251A which measures up to 60A AC, but has a resolution of 1uA. I believe it is 6000 count, so max 6mA at that resolution.
The best way to do low current measurements with a clamp meter is to pass the wire being measured through the clamp multiple times, but that isn't always practical and still doesn't come close to the resolution you can get by inserting a current shunt into the loop.
I own a few of the UT210E clamp meters, but I find their readings are inconsistent. One in particular needs calibration as it has a large offset that I can zero out but otherwise cannot remove even with careful degaussing. I also have a couple of TENMA IN05268 clamp meters with a 1mA resolution, and while they are more expensive than the UT210E, they are my preferred DC clamp meters.
Yes, I own a few meters...