If you want exact readings, and performance data of your panels. A general amp meter is only showing what is happening at that exact moment.
You need to spend a bit if you want the full Monty !!!
Get a Morningstar controller with the network HUB and remote
, or the lower cost is a gadget called "WattsView" that you can see the real time performance, as well as data log to your PC or MAC.
There is no $30 analog meter that will give you all the data you seek.
If you are like me, and are dependent to live off the charge from the panels. You need a good battery monitor, good controller that you are able to communicate with for all the data, or the WattsView. I have all of them !!!