barometric pressure effects on wafer thermostat???

[matt swenson]

i have a wafer style thermostat in my incubator. the temp will be stable for days, then it bumps up a few degrees or down a few degrees. it seems like these swings are going along with the weather. so wondering barometric pressure effects/affects the gas inside the wafer. we had huge winds and a high pressure move in yesterday and my incubator went from 97.5 to 98.7. which , i think , follows my theory. higher pressure would compress the wafer gasses and thus a higher temp. would be need to expand the wafer and switch the relay. is this all in my mind? or is this common knowledge and i'm reinventing the wheel? or is my wafer thermostat faulty?

 

[FluffTheDuck]

So sorry nobody has responded!
So I'm going to say this before I forget, I'm not very good (at all) at science, so I have no idea what in the world how higher pressure would compress the wafer gasses and how it makes a higher temp but there are some links down below that might help. What type of incubator do you have?
Links to help:
https://incubatorwarehouse.com/faq-hatching-eggs


Have a nice day! I hope this solves your problem.

People to help: @casportpony @Eggcessive

 

[casportpony]

Wow, I have no idea! Maybe @sourland , @Chicken canoe, @R2elk , @WVduckchick , or @Pyxis will know.

 

[sourland]

Physics was not one of my strong suits, but it sounds reasonable. Have you tried/considered contacting the manufacturer of your incubator to post this question to them ? Sorry that I have not been of more help.

 

[HenOnAJuneBug]

Is it a sealed or unsealed disc?

 

[WVduckchick]

I’m not sure either, and I understand the curiousity. But I doubt you need to make any adjustments while incubating for minor fluctuations.

@R2elk @Alaskan @007Sean may have thoughts on it.

 

[007Sean]

You are correct that the flexible gas wafer thermostat is affected by barometric pressure as well as by temperature changes. An increase in barometric pressure has the effect of compressing the wafer slightly, this compression acting the same as a decrease in temperature. Thus, the machine responds by building up heat to compensate for the increase in pressure upon the control wafer. This resulting change in the temperature of the incubator is therefore an additional variation to the normal lag between the “on” and “off” of the control mechanism, the point at which the wafer seperates or closes. The ambient temperature of the location of the incubator can also cause the temerature to fluctuate.
ETA- If the wafer gets a pin hole leak or the welds seperate you would have a faulty flexible gas wafer. And you would notice that by the relay being stuck in either the 'on' or 'off' position, most likely the 'off' position.

 

[HenOnAJuneBug]

Info on how those things work isn't that easy to come by. But they are indeed sealed, which means air pressure will affect them. Those things are bellows thermostats.

A thermostat wafer is a very simple machine that has been used for decades to accurately maintain temperature. It consists of a metal "wafer" that contains a small amount of ether. This ether expands and contracts and causes the metal wafer to expand and contract.

 

[matt swenson]

thank you for the info. glad i wasn't just imagining things. the total fluctuation wasn't huge . like down to 96.5 or up to 99. trying to stay a 97.5. that's only a degree and change over or under. And who to say how accurate my thermometers are. also a wild bird can't keep a prefect 97.5 for a month and a half. so i think everything will be fine. the weather also bring fluctuations in humidity in my house so I'm already making adjustments based on the outside conditions.