bad temp sensor, improved air temp?

[rmeden]

Howdy all... long time no post.. (I have lurked a few times...)

I have a Intellitouch computer and the pool temp was displaying very high. Googling showed the sensor is a 10K thermistor where the resistance drops with higher temp. I suspect salt water got into the sensor and is shorting it out.

Those sensors are *rediculously* expensive.

The computer also has an air temp sensor and the installer used the same type of sensor for both. I removed the air sensor and wired it in place of the water sensor and that's working fine now.

The installer just had the air sensor hanging from the Intellitouch panel, right in front of the brick house. Needless to say the numbers it reported were often useless.

I'd like to buy some 10k thermisters ($2 or so at some electronic parts stores... Radio Shack doesn't carry them anymore) and biuld an encsloure for the air sensor to try and get accurate readings. Has anyone done this?

I'm thinking of some white PVC about 3' over the equipment. I'll drill some holes in the pipe for air circulation and put some sort of sun shade on top. I'll put the sensor near the top of the pipe.

Has anyone done anything like this?

(BTW.. I plan on using another thermister to repair the old sensor for when the active one breaks. I'll drill into the housing and replace the thermister with the good one and seal everything tight.)

Robert

[Poconos]

Don't see any problems with your ideas. Just be aware that all thermistors are not created equal so you have to be careful to match the characteristics which is the calibration curve. I have no idea what temperature range the electronics can display but if it will cover 32 to 212 F you can use an ice bath and boiling water as a 2 point calibration. Or, 2 water baths at different temperatures if you have a way to measure the baths accurately. Sounds like you found some sources but I know Newark Electronics (newark.com) has a big stock of stuff including oddball components so you may find something there.
Have Fun.
Al