Water tank temp swing?

[Aleisfood]

Ok I am in the middle of my first incubator build. I ve noticed that I get a Temp. swing of about 9 degree is this normal ? (using hot water temp sensor)
the temp through out my box is with in .4 degree. confirm with my prof. temp probe. ( I am a hvac tec by trade).

 

[rebelcowboysnb]

Assuming you have a light for heat you need to move the thermostat to about an inch from the light.

 

[Junkmanme]

PURELY a guess........

The water will not change temperature as rapidly as will the air........therefore you will get larger "apparent" temperature swings with the water vs air readings. (Edit: But the swings will be much "slower" with the water measurement.)

Seems logical to me,
-Junkmanme-

 

[Aleisfood]

yes I am using lights as heat . I ve built a channel for the water heater sensor and a small computer fan blowing across that and a small fan in front of the light. the box is about 24 inches by 29 inches by 15 inches deep made of wood with 3/8 silver foam board. and yes I am measuring air temp.

 

[fishman65]

try adding a couple of glass jars of water to even out the heat, also a lot of people (me included) will drill a couple of holes in the black bakelight housing of the thermostat to aid in airflow to the metal wafer and help limit the swings in temp to 1/2 to 1 degree. i drilled 3 little holes in my thermostat and get about 1 degree swing.

 

[Aleisfood]

moved finish product