Temperature controller and temperature sensor compatibility

[AligatorAmy]

Hi,
I would like to use the PID Temperature Controller (link 1 below) along with the specific fluid temerature sensor (link 2 below).
(link 1)

http://www.ebay.com/itm/D1S-VR-220-...troller-Control-Thermostat-temp-/230839159277

(link 2)

https://img.banggood.com/thumb/wate...E/54/f583b996-9695-e657-94b9-815918ba042f.jpg

I have both items and would like to use them together for the liquid temperature control.
However, can I do it? I understand that the controller probes changes in the current which flows through the sensor due to electrical resistance change caused by its temperature change. If so, is the specific temperature controller designed for the specific temperature probe type?

P.S. The sensor presented under the second link is from this controller:
(lnik 3)

http://www.ebay.in/itm/DIGITAL-TEMP...IGERATOR-50-110-XH-W2028-BE0390-/262263547714

P.P.S. The controller in link 1 was bought with K type sensor (this sensor is not probably immersion one):

https://picclick.com/Digital-PID-Te...-SSR-2M-K-Type-291883591864.html#&gid=1&pid=1

P.P.S. As the alternative I consider inserting the K type termocouple tip (shown in link 3) into the copper blind pipe and submerging this copper pipe in the liquid. Effectively the sensor would probe the copper T.

Thanks.

Regards

 

[IRstuff]

Did you even read the factory manual?

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[danw2]

The Freezer controller uses an oddball NTC sensor. I would avoid it at all costs.

The Sestos is a typical PID loop controller, using a choice of a number of readily available industrial sensors:
"2. Support multi sensor input (K,S,Wre,T,E,J,B,N,CU50,PT100)"

The K type thermocouple will work with the Sestos. It does not have North American color coding. If you hook it up backwards, applying heat will drive the indicated temperature in the wrong direction, downwards. Just reverse the connections.

Depending on what you're sticking the thermocouple into, there are several standard mounting approaches.

There are compression fittings (Brass or stainless) that are bored for standard thermocouple sheath diameters. They'll work for low pressure, like a water bath.

For higher pressures, there are thermowells, that weld/thread/flange fit into the pressure vessel and the thermocouple slides into a bore sized for the thermocouple.

Letting the thermocouple 'rest' against the bottom of the open copper pipe will provide terrible sensing due to lack of conductive heat from the copper to the rounded sheath tip.

There are hundreds of thermocouple vendors willing to make one in a custom length (if you need one that's longer or shorter) for you at very reasonable prices. You haven't mentioned temperature range or accuracy, but I syspect a type T would serve you better, if for no other reason than its inaccuracy is half that of K or J.

 

[AligatorAmy]

@danw2
Thank you for your detailed answer.
The accuracy would be +/-1degC.
Range is 88-90degC.
In terms of inserting the TCK into the blind copper tube I was thinking of using little bit of glycerine to make a good contact.
I thought to use the stuff that I have in first place which could do the work. Of course it can be also acquired in the shop.
Thank you for your reply.

 

[Paulusgnome]

I would use a PT100 sensor. They are cheap, accurate, and in many applications they are the preferred sensor type.
NTC sensors are OK but can give accuracy issues, particularly if the length of cable between sensor and controller is long.
Thermocouples are great for higher-temperature applications, but since you are only going to 90 deg C they are not really needed.
IMO, the biggest issue with thermocouples is that they need expensive thermocouple wire for the connecting cable, so if there is much length involved it can get a bit unwieldy.

 

[danw2]

The spec'd accuracy with a K type T/C at 0.2% FS for a -50 to 1300°C range is ±2.7°C.
The spec'd accuracy with a Pt100 at 0.2% FS for a -200 to 600°C range is ±1.6°C.

On that basis alone, I, too, would opt for a 3 wire Pt100 for this application. The Sestos unit appears to take 3 wire Pt100's. Not all 1/16DIN temp controllers do, many take 2 wire only which adds an offset error from lead wire resistance.

Using some kind of liquid/oil as a heat transfer medium in the copper tube is an excellent idea.