Temperature sensor accuracy

[yelkenli]

I built an incubator and am in day 6 of the incubation.

I put in a couple of secondary temeprature sensors and, as you might guess, I am getting different readings.

The first is the controls sensor, which is a DHT22.
The second is a nice brass dial-face outdoor weather thermometer
The third is a cheap Acurite, mercury style outdoor weather thermometer.

The DHT22 reads about 1.5F to 2F above the other two. The weather thermometers are about 0.5F different.

I tend to believe the weather thermometers. The DHT22 has various reported accuracies, and +/-2F is one of them.

The cabinet has a fan for circulation. The sensors are all very close to each other.

However, it begs the question, how do you know which one is correct?

Has anyone measured accuracy of thier sensors, and if so, what did you find?

And, the Acurite also has a humidity sensor, which shows a 5% difference to the DHT22. I suppose candling and monitoring air pocket is the way to tackle that?

Some pictures of my incubator are here. The Acurite is shown in the last pic.

Thanks!

 

[eggbert420]

Everyone says check your thermometer against one that you know is accurate. Well how do you know any thermometer is accurate. Other than boiling and freezing points.

 

[LLranch]

Everyone says check your thermometer against one that you know is accurate. Well how do you know any thermometer is accurate. Other than boiling and freezing points.

If it fits in my mouth while it's still brand new I take my temperature with it and expect to see 98.6 that way I can tell how accurate it is very close to incubating temperature

 

[eggbert420]

If it fits in my mouth while it's still brand new I take my temperature with it and expect to see 98.6 that way I can tell how accurate it is very close to incubating temperature

Good idea