Temp Control

Hi I need to keep a liquid at 66degrees C with only +-1'C, I have a 2kw heating element and at the moment i am using a strap on tank 'stat but this is not very accurate at all, any suggestions?

I am in the UK so 240volts is a must and any off the shelf equipment would be appreciated.

Cheers

Ste.

Reply to
Steven McWhan
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You are likely using a "bang-bang" temp controller, the kind that shuts off when the temp reaches a setpoint and kicks back on when it goes below another setpoint. There are problems with overshoot on these systems as well as the inevitable hysteresis band (i.e. the "dead zone" between the setpoints). What you need is a PID controller. "PID" stands for "proportional integral derivative" and it essentially chops the power to the heating element a whole bunch of times and then controls the duty cycle using a sophisticated algorithm that forces the error towards zero over time. I'm not sure what you mean by +-1'C (is this plus/minus one degree Celsius?) but even a cheap PID controller should have no problem with this switch. 240 should be no problem. Try

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they have lots of products that can work for you.

Grant Erw> Hi I need to keep a liquid at 66degrees C with only +-1'C, I have a 2kw

Reply to
Grant Erwin

this

Farnells do a versatile, 'Carel', digital display, temp' controller part No

645-345 at a surprisingly cheap £43 +Vat. I use one in an oven for electronics testing and can attest to the stability of the controlled temperature. regards john
Reply to
John Jardine

Thanks all for your help, farnells have sorted me out.

Regards

would

Reply to
Steven McWhan

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