What we measure :Embryo Temperature
Embryo Temperature can be measured accurately by taking egg shell temperatures on fertile eggs at the eggs equator with a thermoscan thermometer between 16 to 18 days of incubation.
Infertile eggs must not be measured as they have 0.5-1.7 C (2-3F)lower egg shell temperature than fertile eggs.
Effect of incubation temperature on hatchability and chick quality can be seen in the graphs below.
Effect of incubation temperature on hatchability
Effect of incubation temperature on cull rates
Factors affecting uniformity of incubation temperatures:
Incorrect ventilation:air volume supply,pressures,damper settings,exhaust ventilation etc.
Cooling problems-water flow rates,valves stuck open, water temperature,(too hot /cold),scale in pipes etc.
Over/Under utilization of setting capacities.
Physics of air movement/design by manufactures.
Incorrect setting patterns.
Maintenance –poor door seals
Maintenance-correct turning angle