storage temp gauges and sensors?

Hello all--

As I plan the details of the fittings for my 6x6x5 foot storage tank, in addition to the ports for drain, overflow, and inlet and outlet, I'm realizing that I also should incorporate means to track the temperature at one or more points in the tank (seems like at a minimum,one near top and one near bottom), both to get a sense of what the temp in the tank is, and also to control the various other parts of the system (circulators, and, mostly, when the system realizes it has nothing to offer from storage and defaults back to the oil furnace)

I admire Nofossil's computer-based system, but don't believe that I could really pull that off

analog dial temp gauges would be OK with me if the price is right and accuracy is OK; industrial PLC/PID type controls might have advantages, too, although I could use some helpful pointers in zeroing in on the right ones, the right thermocouples, how/ where to best get them "in the tank" and so on.

many thanks for any suggestions

Thanks WoodNotOil and Hot Rod- that Azel looks like a really great little unit, and I suppose if I want to get fancy, I could install various pairs of sensors in multiple places in addition to the storage--with some switching between the sensors and the Azel gauge-- so as to be able to look at other temps like boiler intake and outlet, and the inputs and outputs of the other parts of the system

WoodNotOil- that ought to work, as far as supplying proper voltage, but it'd be a lot easier to mount and wire in compliance with codes and good practice if you got a plate-mount one so that the 24 VAC side is inside a box, and the 24VAC is accessible by screws (that way you don't have dangling wire nuts, etc)

like this one:
http://www.pexsupply.com/product_dtl.asp?pID=1740&cID=282&brand=Honeywell

your existing system very likely has something like that to supply the existing thermostats, and I'd be surprised if the Azel drew enough current to bother the existing 24VAC transformer

WoodNotOil- I read the diagrams/ manuals at both the links you indicated, but am really hesitant to give advice without knowing/seeing how things are hooked together; erroneous suppositions can lead to bad zorch effects.

I'm to a very, very large degree going to/ hoping to be following in your footsteps regarding use of a plate HX and back-to-back circulators for an unpressurized heat tank.

I am very good with electrical things; been doing that with success from batteries to kilovolts since I was age 10 or so.

But on the hydronic side of things, I have been on a steep learning curve with the flow rates, velocities & etc., as well as whether one dares use iron circulators on the unpressurized storage tank side of the HX without having circulator problems or clogged HX problems.

if I remember, you're in the Champlain islands or Franklin Cty; I'd be more than willing to come by (I'm near Montpeculiar) to do an electrical consult & assist, in exchange for being able to talk & see about the pump/ pipe/ flow/ HX layout and sizing you are planning.

please send me a note or PM on whether we may be able to exchange skills here- it'd assist me a lot, and I would be glad to make it reciprocal in offering whatever I can on the wiring side

I don't have an Azel yet, although I probably will eventually- when I get to the control and monitoring parts

I think wire gauge and type is non-critical for the length you're talking about- although it is important to keep it away from any AC cabling that could induce currents that'd confuse things

I can't see any reason not to put the Azel's probe in the monitoring well