I also need help regarding achieving that 99.5 degree target in my old Brower still air incubator. This will be our FIRST attempt at hatching eggs. I have two of those little glass Brower thermometers and two digital thermometers with remote probes. The two with the probes both read about 5 to 7 degrees lower than the Browers, and do not agree with each other! (The two Brower thermometers DO record the same temps.)
The problem with the Brower thermometers was that one of the dang staples that holds the glass tube to the card with the degree marks was right in the way, between 99.5 and 102. I managed to move them up near the top so now I can actually see the critical temperature range!
I hope I am right in trusting the little glass Browers with their red rising line more than my digital remote probe thermometers that do not agree with each other, anyway?
The other question: I have read that the thermometer should be placed at about the height of the top of an egg, which I have done. The air temperature at that height was fluctuating from about 95 to 101 as the incubator cycled. Somewhere I read about placing the bulb of the thermometer in a jar or dish of water - same top-of-egg height - which makes some sense to me. With that arrangement, measuring the temperature of the water in a dish set at top-of-egg height, I had to increase the setting of the wafer switch quite a bit - but am now getting a very nice steady 99.5. HOWEVER I know my AIR temp is now cycling hotter than that 102 degree max we are supposed to strive for.
(I am now trying one of the digitals in the water with the Brower to see if they have more agreement measuring water temp than they do air temp.)
Is it the air temp I should be concerned with? Or should I stick with my water temp measurement for the setting?? Do I need to rush to the store to get a new/different thermometer?
We have at least hedged out bets: a friend with a track record of - mostly - success is going to hatch half of the eggs we are expecting. ;-)
Thank you for any advice you can offer!
Donna