storage tank temperature probes?

[stokes79]

Hello going to be setting my storage tank today and starting to plumb it in here is what I have
on each end of the tank welded 2" weldulets one for supply one for return, tank will sit horizontal, on the return side I will have a 4 foot nipple that threads into the opening so that my return water is coming from the bottom of the tank That leaves me three 3/4 outlets on the top of the tank that I was going to put a pop off valve and two temperature gauges, one for the top of the tank and one for the bottom of the tank, same idea probably just a half inch piece of copper capped on the end threaded into a reducer then threaded into the last 3/4 port.
My question is what kind of temp probe can I get for the bottom of the tank, the leads to the guage need to be five feet long to the sensor my plumber doesn't know where or what to get for the top he was just going to use a well and a "regular" 3 or 4 inch probe that he is familiar with
thanks
casey

 

[WoodNotOil]

There are a couple of options. The best I think for going all the way through the water from the top is a long analog probe like the ones available (broken link removed to http://www.stpats.com/testeq.htm). (like the T-1/2-125-36) You can use digital ones like (broken link removed to http://www.azeltec.com/catalog.0.html.0.html#DIGIT-STAT). The problem I had with a long copper well for the digital probe was that the well was heating and I got a higher than true reading for the bottom of the tank. I put the probe on the return pipe and it was more accurate.

 

[Fred61]

I don't Know if you are looking for just a sensor or a thermometer but this unit fills the bill as a thermometer and a full featured control with a long probe and as far as I know the standard one that comes with it can be extended. The one I have is 24 volt primary and I'm switching a 110 volt circulator. The lower link is the manual that came with mine. When I bought mine three or four years ago I paid $45.00.

(broken link removed)

http://cgproducts.johnsoncontrols.com/MET_PDF/125188.PDF