Thermocouple Temperature Probe

[martin007]

I want to buy a temperature gauge.
One like this.

https://www.aliexpress.com/item/33023900179.html

I want to plug it into my Fluke.
Any suggestions?

[Burgerman]

What for?

[martin007]

Measure the temperature of the batteries in charge.

[Burgerman]

Well any of those probes will be OK for that. I use one for the same purpose and to measure exhaust gas temp on model gas turbines. And to test room temperatures so I can adjust thermostatic radiator valves equally in every room. And once in the pub to measure temp for fun!

[martin007]

The difficulty is finding a sensor with banana plugs...
I want to buy one before the 1st of July the borders close.

[Burgerman]

You wont find one with banana plugs unless its got the adapter "built in". You need an adapter that converts from a thermocouple to a multimeter. Look for a fluke one. https://uk.rs-online.com/web/p/multimet ... s/3368292/

Thermocouples are cheap. Many types and temp ranges.

[martin007]

Look!

> https://www.aliexpress.com/item/32885001821.html

> COSTUMER REVIEWS > Photos

How can you connect to a multimeter if it don't have bananas?

[Burgerman]

Thermocouple have the small yellow plug as standard. They fit all kinds of devices. For e.g my gas turnbines use them. That is a thermocouple connector.

You can get ones with bananas but they only fit multimeters.

Most buy stock thermocouples, and use one of these adapters. https://www.aliexpress.com/item/4001294628894.html

[martin007]

You can get ones with bananas but they only fit multimeters.

If they're cheap, they'll do.
Any suggestions?

[Burgerman]

Any!

It mostly depends on the temperature range your trying to measure. If you get 1 probe and its designed to measure -10 to + 50C then it will be very accurate. But it will be crap trying to measure the gas turbine exhaust at 850C... To do that I would need one that goes to say 1300C. And with a long probe.

When measuring radiators pupes you can get a clamp on one. That needs to measure up to 130C max.

If you get one that measures - 200 to + 1600C then it will not be accurate at room temperatures.

So you need to make up your mind. Does the multimeter allow calibration or offset? You need a glass of water from the fridge, with ice cubes, to check 0C and say, a pan of boiling water to check 100C

Personally for battery measurement I use an LED infrared cheap point and read thingy. https://www.ebay.co.uk/sch/i.html?_from ... cat=130115

[martin007]

Now i have https://aliexpress.com/item/4000251723861.html

[Burgerman]

I got one of those with my fluke.

I also have half a dozen cheap long thin ones for sticking in your , or whatever you want the temp of. For example when nickel electroplating things you need the solution at around 40C. See pic.

Or when measuring gas turbine exhaust you need to be in a safe position and where you can measure high temperatures.

Thats why its easier to get an adapter and buy cheap sensors with yellow two pin connectors on these chinese sites that work at various temperature ranges and then these are cheap enough to be disposed of if/when damaged or overheated.

This is a long stainless steel low temperature range one (for accuracy at 50C). Arrow.
The solution must be around 45 to 50C for shiny plating.

[Burgerman]

2 dollars from chinese auction sites.
Mine has yellow handle.

Various lengths, and various temp ranges. You need different ones for diferent jobs. This one as used above, is a -50C +200C one. So very accurate at 50 centigrade. And also great for food. Check turkey is heated through! I have others that are -50 to 1600 degreesC for "hotter" jobs like the gas turbine exhaust temps.

[martin007]

Link?

How much does the banana plug adapter cost?

[Burgerman]

All sorts of prices. Usually a few dollars. And then all the different standard thermocouples on the chinese auction sites fit.

[martin007]

adapter link?

[Burgerman]

Thermocouple have the small yellow plug as standard. They fit all kinds of devices. For e.g my gas turnbines use them. That is a thermocouple connector.

You can get ones with bananas but they only fit multimeters.

Most buy stock thermocouples, and use one of these adapters. https://www.aliexpress.com/item/4001294628894.html

Thers loads of different ones.

[martin007]

Thermocouple have the small yellow plug as standard. They fit all kinds of devices. For e.g my gas turnbines use them. That is a thermocouple connector.

You can get ones with bananas but they only fit multimeters.

Most buy stock thermocouples, and use one of these adapters. https://www.aliexpress.com/item/4001294628894.html

Thers loads of different ones.

Sorry.

[martin007]

This one's cheaper...


> https://www.aliexpress.com/item/32841905222.html

[Burgerman]

Do you see the innacuracy at low temps if you get a thermocouple that covers a huge temperature range?

-50\\\'C to -20\\\'C ±4\\\'C

-20\\\'C to 0\\\'C ±3\\\'C

0\\\'C to 750\\\'C ±(1%±1\\\'C)

[martin007]

Yes, but I only need a cheap termometer.
My budget is small.

[martin007]

What thermocouples do you have?
Examples and prices.

[Burgerman]

I dont have the reciepts, or records or anything. Some are 15 years old. Some are cheap chinesium ones, a couple are genuine fluke, and all of various temp ranges and types.

When designing, testing model jet engines over the last 20 years I bought several high temperature ones to measure exhaust gas temperatures. Thats important so we get max powwr and dont melt anything.

I got some lower temp ones when I was fitting central heating befor I was injured. Maybe 25 years ago. So I could measure pipe temperatures. These are pipe clamp ones. Measure lower temperature ranges. To set up correct flow/return temperatures on radiators. And also to measure various room temperatures when setting up thermostatic valves.

And also a low temp probe type one thats a stainless rod for measuring the temp of the electroplating chemicals.

No idea of details now. About 6 altogether. used one when dynamometer testing bikes too. To measure air temperature on the air intake. And also to measure engine oil temp etc.

Doing many of these things is helped greatly if your multimeter does logging and graphs. Thats one of the reason I bought the 289 Fluke meter. I can see the room temperature in my living room for e.g. And log it for a day or so. See what its peak and average temperatures are. It allows me to set its thermostat valve to give the best economical ££ setting while being warm enough to be comfortable. I do this for 7 rooms. So the system is all balanced up. Saves me from damp, mould, condensation, and fuel costs. Or I log the residual current on a vehicle thats parked up. So I can see that all the various things that should sleep actually do so. On my van the BCM doesent. It wakes up for hours at a time and pulls power from the battery... These are called trend meters. In the same way I can graph what a typical mobility charger does as it supposedly charges a chair. And decide if its any good or not. Without aving to watch it for 16 hours.

[martin007]

I have visited aliexpress and all the sensors are wide temperature range.
I'm looking for a 0º-50º or range sensor.

[Burgerman]

Many are very similar. A joint between two metals. Some melt at high temperatures so high temp ones use different materials. You may need to calibrate a thermocouple to read low temperatures accurately. On most multimeters this is called offset.

So when looking at low temp ones for more accuracy they are bare. No stainless steel probe that soaks away heat up the probe.

For low temp readings you can use many different types of sensors. That are not thermocouples.

[martin007]

I'm finally going to save the money.
I'll see later.

Thanks.

[Burgerman]

To measure low temps, the bare wire one you already have is great! It doesent have the high thermal mass of the stainless probes so is much more accurate reading air temp or liquid etc. It MAY read a little high/low unless you calibrate and offset the reading.