Which thermostat for my rack, and which thermostat for my incubator

I have a Helix DBS-1000 which I have hooked up to my rack, and today I got a Vivarium Electronics VE-100. I was wondering which would be best for my rack, and which would be best for the incubator I built.

Thank You

I would put the Helix on the incubator, but both will do fine for either.

I would put the proportional in the incubator and the on/off on the rack.

Ok, next weekend I will make the switch, even though I don't really expect eggs for another few months. If you don't mind me asking, why the proportional on the incubator and On/Off for the rack?

A proportional will try to hold a steady temp.
An On/off will fluctuate several degrees during the cycle

I agree with the rest! Helix is the better thermostat of the two due to it being a proportional.

proportional units basically flutter the power on and off very rapidly (60 cycles a second I think but am not sure) this system means the heater is not allowed to heat to its fullest of cool down and generally it will provide a constant temperature at the heat source. The on off units basically provide full power to the heater until it goes 1 degree (or more) over the set point and will do the same below the set point. The real issue is that the probe often cools and heats at a different rate than the heat source and this combined with the 1 degree shift often generates spikes in some cases and situations (not likely with incubators or racks) but spikes of over 10º can be seen. (cool rooms with higher wattage heat sources and slow probe response)