Thermometers

[sirj_76]

Hi everyone. My question is this. I have three old incubators my grandparents used to use. They each had a mercury thermometer in them. Well I'm getting ready to set some turkey eggs so I thought I'd get one going beforehand. I started it up and put all 3 thermometers in it plus a digital. The digital says that it never got above 97, yet when I checked it the mercury thermometers read 99, 100 and 101. Is the digital really that far off? The mercury thermometers only read to 70 so I couldn't check them in ice water. Any ideas? Thanks

 

[Suechick]

You could try calibrating your thermometers. I watched a video posted by "rebelcowboysnb"
You can check it out and give it a try. I think most thermometers that we use give close estimates of temperature. I'm convinced that my digital thermometer was reading at least 3 degrees low. A 30 degree difference sounds ridiculous but you never know. You could certainly feel the difference between 70 and 100 without using any equipment.

Anyway, it's so cool that you want to used your grandparent's incubator!! Such a fun legacy.

Enjoy,


http://cmfarm.us/ThermometerCalibration.html

 

[Buckeyes-R-Us]

depends on the digital thermometer.....some are REALLY crap and my gut would say the mercury is dead on!

the ONLY digit worth owning is the "Spot Check" by Brinsea....there are knock offs on eBay that seem to work just as good but are close to the same price.

Here is a link to the Brinsea site, you can order direct if you like;

http://www.brinsea.com/prod-Spot_Check_Digital_Incubator_Thermometer-25.aspx

"A very accurate, easily read incubator thermometer specifically designed for incubation with a range of 32° - 40°C (90º to 104ºF).
Ten times more accurate than most digital thermometers, it reads to 0.1ºF with an accuracy of ± 0.2ºF. Switchable between ºF and ºC."

This little "Spot Check" is the ONLY digital I have found this accurate at a reasonable price, I highly recommend them!

 

[gino]

You present a very good question.

First I would trust chemistry over electronics for consistancy. If the elctronics are screwed up in your digital it could give you any reading if its off.

The mercury is going to be consistant...however the mercury could be consistantly off by a degree or two (read 98 for 97, 99 for 98....etc.)

Next you will need a standard to calibrate it against. The most common thing that comes to mind are medical thermometers, you know that one that you stick under your tongue to see if you're running a temperature. Do you have one of those? They are usually very accurate at measuring body temperature. You can test it by sticking it under your tongue to make sure it reads 98.6 (or is it 96.8?)

You may have to stick them both in water (or under your tongue) to compare them.

Some of the old thermometers were adjustable, if not it would be a good idea to put some sort of indicator on the thermometer to remind the user the temperature is +1 or -2 or what ever it turn out to be.

Cool idea though....what did they use for a hydrometer? Do you have pictures?.

 

[gino]

I just followed the eariler post the basically recommended using a medical thermometer as well....great minds right? But that got me to thinking about the hydrometer. How do you check that?

Now I know that for hatching chicks it isn't as important as the temperture, but I would still like to know if the hydrometer is accurate.

Back years ago I worked on a large wheat farm and had some pretty fancy instruments for measuring moisture... I can't believe that the $8 unit that I pick up at Walgreens compares to that, but how far off is it and how do I know?

 

[Fiddlehead]

To calibrate a hygrometer, do a salt test! Here is one of many links that explains it:

http://www.stogieguys.com/2006/07/stogie-tip-salt-calibration-test.html

 

[Egghead_Jr]

Most analog hygrometers are adjustable. After your salt test let it stablize to room humidity then adjust it how much it was off, if you attempt adjustment too soon the dial will be falling quickly as your doing it. Pop off the back plate to take apart and then move the face plate to tighten or loosen coil.

 

[Ridgerunner]

The reason you calibrate thermometers is that manufacturing tolerances can throw them off, including the mercury ones. Next time you are at a store that sells several thermometers to measure the outside tmeperature, look at several of them. I've seen as much as 9 degrees F difference in high and low ones on the same shelf in the same climate controlled conditions.

Diffferent thermometers are designed for different accuracies. What this means is not that they read the correct temperature but that they read the same temperature within that range. If there is an error due to manufacturing tolerances, that same error will still show up. That's why you calibrate.

Most of those outside thermometers are designed to be within 1.0 to 2.0 degrees F. Those are not really close enough for an incubator. You need to find one that is designed to be accurate within 0.1 degrees, then calibrate it.

Same general principles for a hygrometer, but I agree they don't have to be nearly that accurate. If they are off a few percent it is not a big deal, but they still should be calibrated.

 

[Lroach711]

Any opinions on the egg-o-meter? http://incubatorwarehouse.com/index.php/review/product/list/id/188/category/46/ It has good reviews. I'm wondering if it's worth buying

 

[tracecom]

I don't really know anything about the Egg-o-Meter, but you can accomplish the same thing with a Brinsea Spot Check and a small rubber ball. I have found the Spot Check to be accurate within 3/10 of a degree. If you want more accuracy than that, see my post on making your own.

https://www.backyardchickens.com/forum/viewtopic.php?id=460659