I wasn’t sure if I could identify I mite, scale really messes with me. Videos help me a lot. So I found one today on my bottom board. Class I went to said one test is placing your bottom board (lite coating of pam) leave in for 2 day. then count the mites. Divided by the number of days and if it equals 50 you need to treat.
here is a video of a mite showing scale and also zoomed in.