freezer differential limits?

[nstech]

Greetings,
I was hoping to get an opinion on what the "acceptable" cut in-cut out range should be on a residential chest freezer. For example, with the dial on the remote bulb (cheap) thermostat set at mid range on the unit in question my recording Fluke meter will fluctuate between 17 below zero and 12 above zero F. (there is about 100 lbs of product in the freezer). When the sensitive fluke probe is inserted into a heatsink (small potato) the fluctuation is reduced to about ten below to about 10 above. The thermostat dial rotates almost a full circle (1-5) and you need to move the dial almost all the way both ways to get a click. This is a new chest freezer. Hopefully I can get a little thermostat/freezer inservice. Thanks!

[Tayters]

Supermarket case controllers I've messed around with are normally set up cut in -20, cut out -22. This is calculated from 60% air off and 40% air on.
Coldroom set similar but 100% air on so net effect is a wee bit chillier.
Yer spuds might need to pull down to temperature more before you can get any reliable readings as your reading of +10 seemed high.

[Tayters]

Ah, always been a bit slow. Now I realise your're in Farenheit not Centigrade. Us English folks only seem to use Farenheit to describe hot weather it seems.

it would appear then you have a range of -11 to -27 Centigrade and -12 to -23 at the product. This seems quite a large differential but there again I'm only comparing to case controllers with probes.

[Peter_1]

This is normal for a residential freezer.