Temp gauge question.

[bigdon-70blazer]

Want to know if there is any way to hook up another electronic temp gauge to my existing temp sender and find out what the temp really is on the Blazer. I don't know if I trust my old one yet, you know, trust but verify. I saw two kinds of gauges in the store, one that had a huge sample line on the back and another that was ran on an electric line. The stock gauge only read cold or hot so I don't know what the temps are supposed to be.