[PolymerKnowHow]

I have an old, old temperature controller for a 25 liter reactor. I would love to build or buy a replacement, but need some help.

Setup:
Input is a thermocouple
Heating via steam, controlled with AC solenoid valve
Cooling via mixed cold/hot water, controlled with AC solenoid valve.
Current controller drives a SSR via DC.

Process includes heat to a setpoint.
Hold at setpoint for a few hours.
Cool to another setpoint.
Hold at new setpoint.
Finish.
Time intervals are not important and setpoints are manually entered.

Not looking for anything fancy. Just a replacement option.

Any suggestions? Manufacturer preferences?

[Stepan]

I use General Scientific Instrument Services www.gsisinc.com, ask Norm Geiger. He will build any design for you.

[typhoon2028]

We Yokogawa temperature controllers on our extruders.  Essentially they perform the same task.

You should probably find out which kind of thermocouple you are using.

How critical is temperature control?  Do you want to measure in F or C?

[PolymerKnowHow]

We Yokogawa temperature controllers on our extruders.  Essentially they perform the same task.

You should probably find out which kind of thermocouple you are using.

How critical is temperature control?  Do you want to measure in F or C?

Thanks, I haven't look at Yokogawa, but they offer similar choices.
Thermocouple is Type J.
Only really need +/- 5 degC.