Need to calibrate your thermometer?

[Penturner]

chickintexas, What you are talking about is what I call response time. Lots of things effect it but basically no thermometer gives an instantaneous reading of temperature. it has to go through some sort of process, absorb heat, expand or retract some sort of liquid or even go through a structural change in order to give a correct reading. some take longer than others. Digitals are usually very slow. In the case of mine a half hour or more. liquid I usually find are much faster but can still be in the area of minutes. the best way to get a feel for your thermometers is to set one in the incubator for a couple of hours. then place any new ones in and time how long they take to read the same temperature.
Also it can be confusing if you have lots of thermometers scattered all over. anything and everything will effect the temperature any given thermometer is reading. Right now I have 4 thermometers in my incubator. 3 are liquid and one digital. I usually keep an eye on things with the easy to read digital but double check it once in a while from the liquids. Two liquids are on the floor and one is at the top right at the viewing window. I know that for a correct temperature at the eggs I want the thermometers on the floor to read 100 degrees and the one at the window to read 98 degrees. neither temp is correct for eggs. but I know the temp at the eggs is 99.5 degrees if I see those incorrect reading at the bottom and top of the incubator. I have verified this over and over again. Now one of the thermometers on the floor was reading 98 degrees yesterday while the other was reading 100. the low one had gotten pushed to close to one of the bottles of water I use as a heat sink. so the air right next to that bottle was only 98. but just 1 inch away it was 100. the bottle of water was sucking up that other 2 degrees of heat energy just like it is supposed to. It is better to know what any thermometer placed anywhere in your incubator should be reading rather than try and get every thermometer to read the same. Knowing that if you look and everything is reading low, you know that the temp really is low. if only one is off there is something wrong with that thermometer for one reason or another. I know it seems backwards that the hotter air is at the bottom, but it is. for one reason there is a lot of heat energy escaping through that viewing window. and there is a bit more air moving at egg level than at floor level. Heat is not like water that you pour into a container and it fills it up equally all over. it fades and strengthens in something like waves and patterns. it shrinks and grows and then shrinks again then will suddenly completely change the shape of the various temperature zones.

 

[chickintexas]

Penturner-The only reason why I had added so many thermometers into the incubator was out of plain curiosity. I was getting all scientist-y.

BTW-I must have been super tired last night but I now realized that your user name is "Penturner." Do you turn wood?

 

[silkiechicken]

Let's add a whole new dimension. Air flow over the eggs, the porosity of the egg, and positioning of the egg in the incubator will also play a role in the absolute temperature of the embryo which rests at the inner top portion of the egg. Your wiggler can say 99.5, but it is a closed system, resting on other materials which could have a temperature gradient, while the egg is porous, has a evaporation of water, and a energy generating chick that effect it's local temperature.

In short, just get a thermometer that is calibrated, put it at egg level, get it to about 99.5, up the temp or lower the temp depending on a few test hatches, and call it good. Less is often more, and testing of what you have and are using is priceless.

 

[Penturner]

chickintexas, Yes I do on the wood turning. Mainly writing pens. you can see one made with feathers on my BYC page but I have tons of others. I had a web site unit the other day, it is in limbo for the moment. Thinking about changing the domain name.
I agree with silkiechicken above though. find your zone according to your thermometer and you are off and running. there are so many many variables you would go crazy trying to account for them all even if you had a laboratory. The subject of egg porosity alone allows one egg to evaporate moisture at a different rate than others. more evaporation means cooler temp for the egg. That may be why hens are better at this than machines if they can feel the difference of one egg compared to another. I read claims that are so widely varied it causes me to wonder how all of them can be successful. I really do believe that what works in one area for one person may not work at all for another person in another area. The real trick is to find out what works best for you and do that, maybe if you have the courage to try, improve on that. But I think I would be real reluctant to mess with a method that I was satisfied with once I had it.