Any recommendations for scanner to read trans fluid temp?

I have to do Transmission service on the Wife's ML. Im looking for "reasonably priced". I know it can be done with a thermal temp gun. I used a digital thermometer on her GLK before the ML with no issues. I just always wondered how accurate that actually was? I don't mind spending a little more if I get features I could possibly need down the road, now that doesn't mean I'm planning on getting a Star scanner. One I was looking at had DPF features I thought could come in handy down the road, manual regens and I believe it would give you % of saturation or flow on the DPF filter.

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1983 300D 255K
2014 ML-350 Bluetec