Serious temperature variation within bator? Can this be true and what should I do?

[CALI CHICK]

I'm using a still air Brower 845 incubator. The instructions said to stabilize the temp between 101-102. I let temp steady at 100 - 102 for 24 hours...My digital thermometer (Accurite) has never settled on 101, which I don't understand?

I set 16 silkie eggs on their sides on Friday (1-27-12) at 9am. The temperatures haven't stayed dead on, so I cover vent holes or open vent holes and occasionally adjust the screw. The temps have dropped to 97 at night a few times and during the day I've had to bump them back down (from 104 but it was very briefly before I got it lower.) It usually stays about 100. I have candled a few and seen some development, but also noticed very loose air cells from being shipped. I decided to place them in egg cartons and just 'tip' the little eggs from side to side to hopefully 'train' the air cell back to the fat side of the egg.

I've been keeping the incubator between 97 and 99 degrees. (I can't get it to read 98??) Then I began to wonder...how much hotter is the temperature on the tops of the eggs? I placed a mercury thermometer on plastic and laid it across some eggs..............It went up to 104 and 106 when the digital thermometer was only showing 99? Can this be acurate and if so, should I adjust my incubator so the digital is reading 95 degrees? Or, should I lay them back down on their sides to avoid the higher heat?

By the way, the eggs do not feel too hot when I touch them. They feel warm like an egg feels right after a chicken lays it. I would really appreciate some insight and experience. This is my first time incubating. I thought I did my research, but the real thing is so stressful.

 

[CALI CHICK]

Has anyone else tested your temps with a mercury thermometer above the egg tops and found the temperature 5+ degrees hotter?

I just wondered if the thermometer was reading actual temperature or if it was too close to the heating coils?

 

[1muttsfan]

It would be a good idea to check your thermometers against a calibrated one, as thermometers can easily be off by several degrees.

 

[CALI CHICK]

It would be a good idea to check your thermometers against a calibrated one, as thermometers can easily be off by several degrees.

Thank you for responding. Where can I purchase a calibrated thermometer? At a feed store? I'm thinking I should maybe get a spare wafer disc/heating element thing, too?

 

[matlock585]

I also use a digital accurite therm/hygrom. I have also never caught mine on 98 or 101. It's always 97,99,100, or 102. I've hatched really great using it too. I'm using it right now as a matter of fact. You can see it live by clicking the link in my signature. I did the "salt test" on the hygrometer and found that It actually read 1% too low on humidity, but I've always trusted the temp and things have gone my way each time. This incubator holds temp much steadier than the one I used last year, but with these same workings and the same Accurite therm I hatched 4/5 on my test, and all 5 made a chick but the last one drowned at internal pip due to me running too high of humidity. On the second hatch I set 14 eggs shipped in over 100 degree heat and 8 made it to lockdown and all 8 hatched unassisted. On my original set up, the temp swung by 8 degrees. Constantly up and down, I set it to run 96-104 and felt like the average of those (100) would be the internal temp of the eggs. I was more than happy with how that ran.
At first I had digital therm and 2 liquid ones spread all over the bator, but after posting and being frustrated I finally just took the liquid mercury therms out and trusted the accurite and all went well. I have eggs in the fridge now from those babies.
Hope you find what works for you! I'll be looking to see what you come up with. A fan would help bunches.

 

[hdowden]

on my dig. the temp needs to read 98-99 for the temp on top of the eggs to be right. i would go by the murcery one and also with it place on top of the eggs as thats the temp you need to go by and get it down to 99-100 from the top of the eggs

 

[1muttsfan]

Here is a link to calibrating instructions. If your thermometer does not measure to freezing or boiling point, then calibrate one that does and compare yours to that one by placing them next to each other and checking for the difference. This is what you have to add (or subtract) from the reading to make it accurate. Btw, Accurite is a great name but they are just as likely as other thermometers to be innacurate.

http://www.foodservice.com/articles/equipment-supplies/How-To-Calibrate-A-Thermometer/

 

[matlock585]

I am using a home made, and I had a hard time getting my temp dialed in. I had to reposition the fan and the guard in front of the light bulb. My water heater thermo is about 1/2" above my lightbulb on a hardware cloth cage. My temp kept spikin and I figured out it was the dang cat laying on the glass and getting warm. Put a laundry basket on it with a weight on top and the rest is history. Perfect temp unless you open, then it rebounds really quick.
Go figure.

 

[CALI CHICK]

I also use a digital accurite therm/hygrom. I have also never caught mine on 98 or 101. It's always 97,99,100, or 102. I've hatched really great using it too. I'm using it right now as a matter of fact. You can see it live by clicking the link in my signature. I did the "salt test" on the hygrometer and found that It actually read 1% too low on humidity, but I've always trusted the temp and things have gone my way each time. This incubator holds temp much steadier than the one I used last year, but with these same workings and the same Accurite therm I hatched 4/5 on my test, and all 5 made a chick but the last one drowned at internal pip due to me running too high of humidity. On the second hatch I set 14 eggs shipped in over 100 degree heat and 8 made it to lockdown and all 8 hatched unassisted. On my original set up, the temp swung by 8 degrees. Constantly up and down, I set it to run 96-104 and felt like the average of those (100) would be the internal temp of the eggs. I was more than happy with how that ran.
At first I had digital therm and 2 liquid ones spread all over the bator, but after posting and being frustrated I finally just took the liquid mercury therms out and trusted the accurite and all went well. I have eggs in the fridge now from those babies.
Hope you find what works for you! I'll be looking to see what you come up with. A fan would help bunches.

matlock585 - Thank you for responding to my question. I have actually been following your thread and seen some similarities b/n our hatches (therm/hygrom, temp variations, etc). I even have the same 'shelf liner' under my eggs-LOL. I almost posted on your thread or PM you so I'm encouraged to hear from someone who is experiencing a similar incubation experience. My eggs however, are on Day 4 or Day 5. (They were set Friday morning at 9am).

Just an update - The heater box cracked the top of one of my eggs and put a toothpick-size hole in it. I felt it would be best to remove it since the membranes were pierced. Well, I peeled off the top of the shell and was happy and also sad to see a developing embryo. My son and I looked in awe at the tiny veins branching away from the beginnings of the heart and speck of an eye! Then, when we candled a few this afternoon, we saw development in several eggs. This tells me that even though the temperature numbers are not "textbook" it is working.

In your opinion, should I put the eggs back down on their sides and stick to 99/100 degrees? That's what was working, so I'm wondering if I should go back to it?
Thank you again for posting to my question.

 

[hdowden]

i would put them back on their sides