Pool Temperature Monitoring

[CJDahl]

I need to monitor IG pool water temperature. where is the best location for sensor installation? I was thinking the filter location or skimmer may be superior to the pool itself. Any advice greatly appreciated. Thanks!!

[Poconos]

Depends on why you want to monitor. If you're interested in freeze protection then the air temp would be my choice. If you're just interested in water temp then a)--if the water is circulating then the skimmer or b)--the pool itself a foot or so below the surface. Keep in mind the bigger the mass of any substance the longer it takes to change temperature.
Al

[CJDahl]

Thanks. If I go the "in the pool" route any ideas how I would go about mounting wire/temperature sensor to pool liner? thanks

[Poconos]

Unfortunately I don't any good ideas for a mount. Perhaps some mount utilizing a return jet eyeball retainer to hold it where you want it or maybe mounting to the skimmer faceplate somehow. You could also put a dime sized vinyl patch over the wire to hold it against the liner. I don't need to monitor my temp constantly and when I do I just have a thermocouple taped to the end of a 1/2" PVC pipe a couple feet long and stick it where I want it. If the sensor is an exposed thermocouple junction you should coat it with silicone seal to prevent the chlorine from attacking the wires. Best I can suggest.
Al

[fcfrey]

I have a "K" type thermocouple mounted in the discharge of my circulating pump. The purpose gives the solar controller a continuous temperature reading of the pool water. Another thermocouple reads air/solar heat potential to feed the controller a delta T (temperature differential) to determine whether to open the valve to the solar system (there is also setpoint logic involved).

The installation of the thermocouple was simply drilling a 5/16 inch hole and securing the device with a SS worm gear clamp with an "O" ring seal.

The thermocouple is available from Pentair (part # TS-5T).

See the silver band right above pump head.

http://i129.photobucket.com/albums/p206/fcfrey/SolarSystem_Pump.jpg

[mas985]

Mine is installed after the filter but in the same manner as fcfrey. I suspect the PB installed it after the filter so that the thermocouple will not collect dirt as quickly as before the filter.

[CJDahl]

Thanks for responses. This is very helpful. I'm just concerned about drilling into PVC causing a leak. No problems with O ring leaking??

[Poconos]

For plugging the drilled hole you can use a mixture of PVC cement and ground up PVC pipe to make a thick slurry. Squish it into the hole and let it set. I've used a rasp file to grind pipe or for finer stuff use a saw or a finer file.
Al

[mas985]

Thanks for responses. This is very helpful. I'm just concerned about drilling into PVC causing a leak. No problems with O ring leaking??

There should be a gasket or o-ring supplied with the thermocouple which will seal the gap between the pipe and thermocouple. And no, it should not leak if installed properly with the hose clamp.

[CrisL]

My sensor has been installed in the supply pipe before the filter for five years now, with no leaking.

[fcfrey]

As mentioned in previous posts, the thermocouple came with an O ring. I take mine off every year when I close and lube the O ring with plumbers silicone. I have never had a leak.

Another method I have used is to carefully drill a 7/16 hole then tap with a 1/4 pipe tap, this allows you to use conventional pipe fittings & teflon tape to make connections. I used this method to install the injection port for my bleach injection system. Again ---- NO LEAKS.