PID question

[prrriiide]

Looking at this PID controller:

and reading the description:

This is for a dual display universal digital programmable temperature controller that supports many type of thermocouple sensor. It can be powered by 80-265V AC/DC or 12-30V AC/DC, Comsumption 5VA. DIN 1/16. Apply with step control, 2 independent PID control for heating/cooling over temperature,pressure, level, flowm, etc.

Features

1. Apply with step control, 2 independent PID control for
heating/cooling over temperature, pressure, level, flowm, etc.. Widely used
in auto system in line of light industry, chemistry, machine, metallurgy,
ceramics, pertrification industry, or temperature control and adjust system
of food & beverage; oven; furnance, plastic extruder heating process etc.
2. One key operation, Auto-tuning PID/ Fuzzy PID control. Easy operation,Reliable performance.
3. Input: TC(K. J. S. E. T. R. B)/ RTD (Pt100. CU50) universal. input: (24V/30mA supply available for standard transmitter).
4. Accuracy: 0.3%.
5. Control output: SSR. Alarm output: RELAY. 7 kinds of alarm
mode: high / low / high deviation / low deviation/ interval / out of interval /
breakage alarm.
6. Dimensions: DIN 1/16 48*48*80mm. Case class: IP65.
7. Power supply: regular: 80-265V AC/DC 50/60HZ.
8. Package Included: 1 x SNR PID Temperature Controller.

and wondering how you get the temperature reading from the point to be controlled to the controller. Is there a separate probe, or just how does this thing work? Is that what is being described in #3 above?

 

[3BB001]

Yes, there is a separate probe you connect to this unit to read the temperature. Search for RTD or Thermocouple.

 

[ChemE]

Type K thermocouples are best for the sort of temperature ranges that we are interested in.

http://www.auberins.com/index.php?main_page=index&cPath=20_3

You should expect to pay less than $20 for an excellent thermocouple capable of ±1°F at or below the boiling point of water.

 

[bucfanmike]

all my research has pointed to the RTD (pt100 sensors to be the best for our application. Im sure others who have done will chime in, but my plan is building with those over the k type.

 

[ChemE]

I believe that type K thermocouples are more sensitive than are thermistors. It has been a few years since I took controls so I'm relying on memory rather than recent Google-Fu so I could be wrong.