Unlike your wife, I will say go buy a new one. BUT common sense and your wife will ask why you need one at all? She might ask maybe the voltage is the temp and the temp is the depth.
Lets see, if you want depth lower a weighted worm, if you want temp stick your finger in the water.
I am nice and just telling you how MY wife would answer your question. That is also why I am the only one that see's the bank stmt and credit card bills.