Thermocouple readers are very expensive

[grizedale]

Hello,

We wish to measure temperature of our smps semiconductors with thermocouple wire

eg
Buy Thermocouple & Extension Wire T PTFE twin twist fine thermocouple, 25m RS XQ-019-RS online from RS for next day delivery.

(RS 363 0402)

Do you know of the cheapest possible meter that can read one, and possibly several of these thermocouples when plugged in to it?

 

[eceblr2011]

Hello,

We wish to measure temperature of our smps semiconductors with thermocouple wire

eg
Buy Thermocouple & Extension Wire T PTFE twin twist fine thermocouple, 25m RS XQ-019-RS online from RS for next day delivery.

(RS 363 0402)

Do you know of the cheapest possible meter that can read one, and possibly several of these thermocouples when plugged in to it?

You can try for A312TPI-ND, BK630-ND or 290-1416-ND. Generally these sorts of equipment and measurement probes are costlier.

 

[FvM]

Me (and some of my customers) are using the below inexpensive 4-channel handhelp temperature logger for thermocouple measurements. As a minor restriction, there's no gavalnic isolation between channels.

 

[grizedale]

FvM, thanks thats the best value for money ive yet seen.....though still £176 for 4 channels..... and presumably as long as we have the thermocouples on the fet cases it wont matter about the lack of inter channel isolation?

Just to note, we are using the thermocouple wire and plug as follows.....

Thermocouple wire:
RS 363 0402

Buy Thermocouple & Extension Wire T PTFE twin twist fine thermocouple, 25m RS XQ-019-RS online from RS for next day delivery.

Plug for thermocoupel wire
RS 381 7508

Buy Temperature Sensor Accessories R/S min quick wire connector plug RS XQ-163-RS online from RS for next day delivery.

 

[FvM]

The K204 data logger, as most thermocouple thermometers, uses type K (NiCr/Ni) thermocouples. I didn't reliaze at first sight, that your link is referring to type T instead. Although the characteristic is similar to type K, the temperature measurement won't be exact with it. Why are you using type T? It's rather uncommon in my view, because type K can be considered as an industry standard.

The connectors in your last post are type R/S (high temperature PtRh/Pt), which won't be correct anyway.

 

[grizedale]

FvM: Thanks ive changed to type K now, regarding the wire.

The connector is prooving difficult to source.....i basically need whatever type of plug goes into the following thermocouple reader......

https://www.farnell.com/datasheets/460995.pdf

I always presumed they were those green ones with the dual blade connector...one blade being narrower than the other.........I suppose i should search under "K Type thermocouple plug"?

 

[FvM]

Mechanically, the miniature thermocouple plugs are identical, they only differ by connector metal. Using the right connector type according to the thermoelement/extension wire type isn't that important, as long as temperature gradients across the connector are small. But if available, I would use the correct type. 455-9764 is the RS type K type as far as I see.

 

[grizedale]

Thankyou FvM, i will use that one...i'm relieved now as i wouldnt wanted to have been using the wrong type....i'll also have to remeber the polarity of it...because if i remember rightly, the green and white wires have to go a specific way round or else its bad news.

Also, i am wondering if the best tool to strip the PTFE wire is a kynar wire type stripper?.....as i remember that stripping the ptfe back is a nightmare of a job

kynar stripper:
CK TOOLS|T3756 25|WIRE STRIPPER, 0.25MM | Farnell United Kingdom

 

[FvM]

Yes, a wire stripper is a good tool. I prefer adjustable types like Farnell 1416123. You can also carefully notch the cladding with a paper cutter, but if you scratch the metal wire, it's likely to break later on.

The plugs have a polarity marking "+" at the smaller pin, the green type K wire connects to it. Thermocouple - Wikipedia, the free encyclopedia