Temp Sensors OPII

[edge]

I have 2 of these that are failing, and I'm aware of the 'issues' some have had with the accuracy of these devices........is there another alternative or am I going to have to purchase more of the same?
 
What are others using?

 

[edge]

Recommendations......anybody?

 

[ano]

From what I have seen, HAI temp sensors are very consistent, but their initial calibration is not great. Usually they are a few degrees off and this can be corrected with their calibration.  Once corrected, they are pretty accurate.  If you are saying they are inaccurate different amounts different times of the day, either 1) they are receiving significant electrical interference to the sensor or along the wire, or 2) they are mounted incorrectly, likely where the sun can hit them. 
 
The sensors themselves are pretty simple and they are something you can build yourself with not that much work.  They put out a voltage between about 1V and 4V based on the temperature. Higher temp. higher voltage.  The zone acts like a volt meter, reading voltage and converting that to temperature.  I don't know the conversion, but its easy enough to find out.  Use a variable power supply, but in a voltage across the zone and see what temp it reads for each voltage.  Also, with a few resistors, you can do any type of temp adjustment you can imagine. 
 
So you can build your own sensors, or calibrate the HAI ones however you need.