How warm should a dew shield heater get?

[AlistairHowie]

I have an Astrozap dew heater controller and their flexible dew shield with integrated heater. I have tried the heater in my house, running off my battery and it gets noticeably warm, so all is working properly.

But when I use it on my scope, I don't notice any heat in it at all, or on the exterior of my OTA surrounding the corrector plate. The only difference between my inside testing and outside set-up is that I'm running the dew shield off a cigarette lighter spliter, the other socket powering my CPC scope. All the right lights are on the socket and the dew controller, so it seems like it's working ... just no discernable heat. But ... having said that, I've not had any dew on my scope.

Is it just simply a case of the heat being conducted away to the corrector plate, and of me using the heated shield outside in zero degree temperatures that is meaning I can't particularly discern any heat, either on the scope or on the dew shield whenever I've undone the velcro and felt along the inside? I had the heater on max setting, so 1.5Ah, for at least an hour tonight outside.

[Freddie]

Sounds like everything is fine as it is usually difficult to feel any heat in the tape once on the scope and outside.

[rowan46]

if it's keeping your corrector plate clear it's working

[AlistairHowie]

Thanks - that's what I thought!