Which is more accurate...Digital or Mercury??

[Jarhead]

I have one digital which is almost right on for humidity, and 1 that is off by like 15%. Best to test them for accuracy.

That is also true though for lots of analog hygrometers. If you go to a pet store or a hardware store, just look at those on the shelf. They will be showing a wildly variable humidity reading from one to the next.

The most accurate way to measure for humidity is not the easiest. You need a wet bulb thermometer and a dry thermometer. The wet bulb has a wick in some water and the other end attached to the thermometer. You take the readings of both and either do the math or look at a chart to figure the humidity.

 

[Ken H]

Accuracy depends on many factors. I prefer the thermocouple type as they produce a definate voltage at any given temperature and never need calibration. They are however a little more expensive. The 'Ranco' thermostat I bought for my home made incubator was $64.00. It controls to within 1 degree and will always be accurate. The sensor can be located up to 500 feet away from the control so you could see the temperature in the house without going to the incubator location. An alarm circuit could also be wired in to notify you if your heat source failed.

 

[beckychick]

Okay,

Speaking with my husband (Medical Tech), he tells me the digital is more accurate as long as it has been calibrated. The regular mercury thermometer leaves a lot to personal interpretation.

 

[FenDruadin]

Oh, thank you! I am going to go get a Geratherm. I was thinking of ordering a $20 calibrated milk thermometer from Hoegger's for the purpose, but a $6 one from CVS is easier and cheaper! Thanks for that info!

 

[Jarhead]

Problem is getting a digital that is calibrated. All the stuff available at the consumer level varies wildly in what measurement it gives you. It gets worse when the batteries are not fresh. In a medical setting the thermos they have are calibrated and cost more than any of use would want to spend. I looked at a few, and man you are talking at least $150 bucks for a little digital thermo that you stick in your mouth. Problem is it is one of those you had to press a button and a reading is displayed (no constant measurement), and the medical ones don't have those little wired probes or display a constant temp. It was guaranteed accurate within +/- .1 degree. So was the little liquid metal Galinstan glass thermo for $6. The individual has decide which is a better value for them and their situation, no single item will fit the bill for everyone. One thing that is certain is everyone needs to test their digital thermos for accuracy, whether it is for incubation or their family. Don't trust them out of the box, it's not worth the risk!

 

[speckledhen]

Probably the best thing to do is get a decent quality thermometer made for incubating, like the Egg Temp. If I start doing alot of hatching, I will be buying one. At Stromberg's, it's about $35, could be cheaper elsewhere.