I have 3 different thermometers in my incubator and ALL of them is either 1 degree or lil more then 1/2 a degree from the others, None are even close to what the other says. Is there a way to Calibrate a Thermometer? its still air and the temp on one thermometer told me it jumped up to 103.2 once, of course it wasnt but a hour or so because i checked before, but how FAR can the temp go up before eggs are no good? or how long will it have to sit on a high temp before being bad? also what other ways is there to keep the temp stable? its fine during the day but at night it drops to 99.0 while im asleep, or goes up (trys to) to 103.