Precision Incubator with advanced temperature and humidity control

Hi!

I recently built my own incubator and I thought I would share my results for those that might be interested.




I'm incubating a mixture of mostly Black Copper Maran and Ameraucana eggs, with a few Welsummer and White Egg layer eggs thrown in to make up the numbers. This is day one (3 hours to be precise).





In this article (http://www.thepoultrysite.com/focus/contents/ceva/OnlineBulletins/ob_2005/Article-No3-Nov05.pdf) I learned that eggs start to generate their own heat at around 15 days or so, so the air temperature needs to be reduced accordingly. To monitor the egg temperature I've taped a thermocouple to the shell one of one of the eggs.




With the this PID I'm able to control both the temperature and measure the humidity inside the incubator. I also have the ability to automatically control the humidity using an ultrasonic fogger.




The whole temperature setup can be monitored via the PC. The blue trace is the air temp just above the eggs and the green trace is the shell temp of one of the eggs. As you can see the the incubator is in the process of warming up. Its been on for about 3 hours. The target shell temp is 37.8 C (100 F).



The whole system has been calibrated using a NIST thermometer.

Just a question, do you not worry that the single egg you have the thermometer taped to may be in a hot spot in your incubator? I would be so worried that that single egg would be in a hot spot and the rest of the eggs would be cooling down as the temperature is set for the optimum for that single egg. Or do you have an overall thermometer to keep the whole unit at a good steady temperature, and are just taking that single shells reading into account?

This is very much an experimental setup, so I'm still making minor adjustments to the position of things. Its now been 5 hours or so and the eggs have reached there target temp of 37.8 C (100.04 F). The air is circulated using a small fan. The egg with the attached sensor is off to the side of the fan, not directly under it. I do not believe that there are any specific hot spots, but I can see from other thermometers in the unit that the temperature falls off slightly towards edges of the incubator. The temperature sensor that controls the PID is in a different location and fortunately it also reads the same as the egg shell sensor. I have a separate air temp sensor and it reads about 2 degrees C higher than the egg. My small egg thermometer sitting directly on the wire mesh read 100 F. Here's the lasted temperature snapshot. while the air temp moves up and down quite a bit the egg shell temp fluctuates only by about +/- 0.15 C ( or +/- 0.3 F). I should note that I preciously calibrated all my temperature sensors using the glass NIST thermometer.

I've been tracking the temperature for about 10 hours or so. The blue trace is the air temp and the green trace is the egg shell temp. Here are the results:


This looks like the best I can do with this setup.37.75 +/- 0.25 C (99.95 +/-0.45 F) egg shell temp. The internal egg temp will I think be close to a constant 37.7 C. This is not too bad.given that temperatures in the house fell quite a bit during the night (10 F or so). The humidity fell off to around 45% so I've added a small container off water stored off to the side in the incubator to bring it back to around 60%.

My Bator could never hold temperature this well, as such my hatches were rather pour. Frankly I found it rather too stressful as often the temperature would shoot up to too high a level. I'm hoping for better results here. Although the eggs where collected when the weather was still very cold.

Id love to see a how to/diy for your digital temp/humidity monitor.

I think that perhaps the right time to write a how too on the temp/humidity controller is after I've gotten through this current hatch. There are already several changes I would make to the set up.

In my last post showing the 10 hr temperature chart one can see that there was a cycling of the egg shell temperature. This I've discovered is due to the rolling motion of the egg turning tray. I've since moved the temperature sensor to the bottom of the egg to hopefully mitigate this problem and get a more accurate read on the egg temperature.

Its very likely that the egg will read a lower temperature since it is less exposed to the air from the fan, and that my egg is not really at 37.8 C as I has hoped. With any temperature system they can take several hours to settle down after a disturbance. Right now the bottom of the egg shell appears to be at 37.2 C (99F).

Hi can you tell me the temperature sensor type?

have the same controller that you have but can't program it to start my heater or humidifier , could you share the settings you use

thank you

leoroy