I purchased this one and I have built a few wheels with it. It works fine. The most important thing to remember, is that a tensionometer needs to be accurate to itself. Yes, having proper readings as important, but they are generally close enough. As long as they can properly tension one spoke in comparison to another spoke on the same wheel, you should be OK.

beiyoule Spoke Tension Meter Tool... https://www.amazon.com/dp/B08BZ7RLQQ?ref=ppx_pop_mob_ap_share