The Yocto-Thermocouple device is a USB temperature sensor. It lets you perform via USB instant temperature measurements on two thermocouple inputs, as well as record the measures on its internal flash for later retrieval when connected again by USB. Thanks to the use of thermocouples, this tiny module can measure the temperature of liquids, small objects, food, mechanical pieces, ovens, and so on. It is very reactive to quick temperature changes (detection in 30 [ms], stable measure in 100 [ms]).

The use of thermocouples makes it easy to measure a temperature away from the module. However, if you need to measure something dozens of meters away, you can avoid to use an expensive long thermocouple by moving the thermocouple inputs further away from the USB connector: simply split the board into two parts and solder a 4-wire cable on the designated pads.

This device ships with two 50cm fine-wire twisted-pair thermocouple cables type K, which can be used to measure temperatures between -75°C and 260°C (PFA insulated, measure point non-insulated). To use a wider measuring range with the device, you can use any of the more sophisticated thermocouples that you can find on a specialized shop.

This device can be connected directly to an Ethernet network using a YoctoHub-Ethernet, to a WiFi network using a YoctoHub-Wireless-n and to a GSM network using a YoctoHub-GSM.

Yocto-Thermocouple Yocto-Thermocouple Yocto-Thermocouple

USB cables and enclosures to be ordered separately.

CHF 48.65

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Hardware release:Rev. E
Product name:Yocto-Thermocouple
USB connector:micro-B
Sensor:Type K,E,J,N,R,S,T
Refresh rate:5Hz
Accuracy:1°C 1%
Protection class, according to IEC 61140:class III
Normal operating temperature:5...40°C
Extended operating temperature2:-30...85°C
Max temperature:1768°C
Min temperature:-200°C
Supported Operating Systems:Windows (PC + IoT), Linux (Intel + ARM), macOS, Android
Drivers:Driverless, no driver needed
API / SDK / Libraries:C++ Obj-C C# VB.NET UWP Delphi Python Java Android LabVIEW
API / SDK / Libraries (TCP only):Javascript Node.js PHP
RoHS compliance:RoHS III (2011/65/UE+2015/863)
Suggested enclosure:YoctoBox-Short-Thick-Black
Harmonized tariff code:9032.9000
Cables and enclosures:available separately
Made in:Switzerland

1 These specifications are for the current hardware revision. Specifications for earlier revisions may differ.
2 The extended temperature range is defined based on components specifications and has been tested during a limited duration (1h). When using the device in harsh environments for a long period of time, we strongly advise to run extensive tests before going to production.

Accessories and related products

YoctoBox-Short-Thick-Black, Enclosure for Yoctopuce device (short, thick, black)Micro-USB-Hub-V2, Micro USB hub (multi-TT) with solder pads, for DIY useFix-2.5mm, screws and spacersUSB-A-MicroB-50, USB 2.0 type A to Micro-B data cable, 50 cm

Related articles and application examples


User manual (HTML)
User manual (PDF)
Product brief
3D file (STEP)
RoHS certificate
REACH certificate
Most recent firmware54851 (06/02/2023)
Programming libraries61813 (07/05/2024)
Command line API61813 (07/05/2024)
VirtualHub application61813 (07/05/2024)

Add a comment 37 comments

1 - edward_valarm Wednesday,may 07,2014 23H28

The Valarm Pro Android app supports up to 4 Yocto-Thermocouple sensors at the same time so you can alert and upload data to the Valarm Tools Cloud with up to 8 channels of temperature! http://www.valarm.net/blog/new-valarm-pro-app-version-1-3-0/

2 - pam Friday,may 30,2014 17H16

Hi I'm wondering how long the thermocouple cables can be? I have a space that I have about 100 feet distance to travel. Also what gauge wire would you recommend?

3 - martinm (Yocto-Team)Friday,may 30,2014 17H44

@pam 20 AWG or thicker wire should be fine as long as you are free of electromagnetic interferences.

4 - petero Sunday,february 01,2015 11H16

Hello. Can this thermacouple (or another) sensor be used to accurately measure soil temperature vs. ambient air temp? What precision would it have?

5 - martinm (Yocto-Team)Sunday,february 01,2015 13H06

@petero : if you're interested in precision, you should choose a Yocto-PT100:

6 - maturin Tuesday,april 21,2015 21H44


Im interested in displaying temperature probably not data logging or usb. Can I add a LCD to display current temperature?

7 - martinm (Yocto-Team)Wednesday,april 22,2015 5H53

@maturin You could use a mini-pc such as a Raspberry PI to drive a Yocto-Thermo-couple and a Yocto-Display such as described here: http://www.yoctopuce.com/EN/article/turn-your-raspberry-pi-into-a-network-multimeter but honnestly, if you are not interested in connectivity, you should find yourself a regular handheld thermometer.

8 - shelendra Saturday,may 16,2015 6H37

You have provide great examples , why don't you provide an app like valarm.. it will be helpful . i want to save the data on smartphone and than later upload it to xively or in real time ... like i m able to do using pi or pc .
Please consider this . i tried valarm and i don't think it real worth money

9 - martinm (Yocto-Team)Monday,may 18,2015 19H14

@shelendra: we have no plan for any kind of turn-key software solution. Here at Yoctopuce, the plan is to focus on the hardware and make it easy to integrate. That way our customers only have to care about the software and can write their own solution suited to their need.

10 - eipa Thursday,january 07,2016 22H51

I want to use this device for cooking so: are these thermocouples water-resistant or should I start by looking for suitable thermocouples?

11 - mvuilleu (Yocto-Team)Friday,january 08,2016 7H54

@eipa Thermocouple wires are water resistant, but personally I don't like to put use any type of plastics for cooking, so I rather use mineral insulated thermocouples for that type of application. Note that if you are cooking on an old electric stove (which is likely to be grounded), your measures might be incorrect due to ground currents. This is also solved by using a mineral insulated thermocouple.

12 - astroboy Sunday,march 13,2016 23H47

Hi there. I have the thermocouples set up and am graphing data on my phone using your Yocto-graph Android app. Is there a way I can easily download the values that make up the graph so I can use the data elsewhere?

13 - seb (Yocto-Team)Monday,march 14,2016 8H02

@astroboy: This demo application cannot export data. If you want to export measures of the datalogger the easiest way is to use our command line library. Plug your Yocto-Thermocouple to a computer and use the command line YTemperature to export all data in csv format:

YTemperature.exe --csv all get_recordedData 0 0

14 - el toro Wednesday,may 04,2016 13H15

what is the communication protocol of this device?

15 - martinm (Yocto-Team)Wednesday,may 04,2016 14H10

@ el toro: same as all yocto-devices: HID vendor specific

16 - gillio Wednesday,august 10,2016 6H17

It is possible to connect (RT) Standard Bayonet Type (PT-100 sensor, 3 wires) to yocto-thermocouple?

17 - martinm (Yocto-Team)Wednesday,august 10,2016 6H24

@gillio: No, thermoucouples and PT100 are two different technologies. But you can use a Yocto-PT100 to read your 3 wires PT100 :-)

18 - swa72 Monday,january 16,2017 12H59

Can someone recommend two probes that

- avoid possbile grounding problems (i.e. are mineral insulated thermocouples)
- work with Yocto-thermocouple
- measure air temp in an oven (like http://www.thermoworks.com/TX-1003X-AP)
- measure meat temp (like http://www.thermoworks.com/TX-1001X-OP)

and can be easily bought in EU?

I'd like to get an idea for the probes first before buying the Yocto-thermocouple ;-)

Best, Stefan.

19 - martinm (Yocto-Team)Monday,january 16,2017 13H45

Hi Stefan

Have a look at www.labfacility.com and www.tcdirect.com

20 - swa72 Monday,january 16,2017 15H21

Thanks for the quick answer. Can I use the default probes and its connecting cables (PFA isolated) in water and hot air? Air temp < 250°C and water temp less than 100°C.

21 - martinm (Yocto-Team)Monday,january 16,2017 16H12

@swa72: yes, but since the thermocouple wires provided with the Yocto-Thermocouple are *not* mineraly insulated, you'll have to be extra-careful with water and make sure the container is properly isolated.
More details here: www.yoctopuce.com/EN/article/the-yocto-thermocouple-and-ground-loops

22 - philbot999 Wednesday,may 10,2017 12H14

I bought this thermocouple and I want to use it with my Raspberry Pi Zero W using the latest ( April 2017 ) Raspbian Release. I understand that the newest Raspbian does not support these devices, but the older ( March 2016 ) Raspbian release does. I have everything configured on my newer Raspbian and do not want to go back to an older release. Is there a workaround so that I can use this thermocouple with my Raspberry Pi? Thanks.

23 - seb (Yocto-Team)Wednesday,may 10,2017 12H29

@philbot999: Unfortunately, we have no workaround.

We have done lots of tests with an USB analyzer and we have found that time to time the Raspberry Pi send corrupted USB packets. This problem occur only with Pi Zero and latests Rasbpian. The same Image with the sames device work perfectly on a Raspberry Pi 2 or 3.

We will submit a bug report to the Raspbian team and try to help them to fix this issue.

24 - ferny Wednesday,october 18,2017 7H14

Smart product! Does this device have cold junction compensation built-in?

25 - martinm (Yocto-Team)Wednesday,october 18,2017 7H30

@ferny: yes, see:

26 - arsalan Friday,may 11,2018 16H38

Hi Guys,

I have recently connected a yocto-thermocouple to temperature probes in a coffee roaster. I am using a program called artisan to track roasting.

The temperature values are way off and jump around alot. There is no groundloop. I dont know how to fix this. Link to reddit post : https://www.reddit.com/r/roasting/comments/8ij9k4/odd_artisan_issue/


27 - martinm (Yocto-Team)Friday,may 11,2018 18H51

@arsalan: what make you so sure that you don't have ground loops? temperature jumping around is typical of such problems. Temperature average being off can be caused be a wrong thermocouple wire settings (default setting is type K) This can be fixed with the VirtualHub.

Don't hesitate to contact Yoctopuce support directly for more help.

28 - ansall2006 Tuesday,may 26,2020 0H39

He intentado desde colombia comprar el dispositivo Yocto Thermocouple pero nada, no me acepta ninguna tarjeta de crédito. No se quien rechaza si Uds. como comercio o la entidad financiera. Valdría la pena que pusieran los elementos en Amazon, e-bay o cualquiera de esas empresas con las cuales no hay inconvenientes con el pago. Llevo algunos años tratando de comprar este elemento y nada no es posible.

29 - martinm (Yocto-Team)Tuesday,may 26,2020 7H07

@ansall2006: unfortunately, the card payment process is handled by our bank server, we have no control over it. That being said, we do have resellers and at least one of them is selling on Amazon.

30 - mtf Tuesday,march 30,2021 12H44

(Sorry I mistakenly posted my comment on the French page.)

I just recently heard about Yoctopuce and I really like what I saw on your store and your blog, as well as the spirit you described in the About page about the brand and the way the products are designed. Thanks for offering this kind of products.

I am very interested in Yocto-thermocouple (×2) that I would combine to a Micro-USB-Hub-V2 for use connected to a SBC running Debian. However, to be fully honest, I'm still hesitating between this setup (Yocto-thermocouple + Yocto USB HUB + connectors) vs a Phidget 1048_0B (https://www.phidgets.com/?tier=3&catid=14&pcid=12&prodid=1028) which also allows 4 thermocouples in a pretty compact package (perhaps even more than Yocto, which is already very compact), just a USB connection to the computer, and good Linux support in multiple languages, for just a little bit cheaper.

My decision is not made yet and I'm still considering other options, but I would be curious if you could maybe comment on those two specific alternatives and help me see what could be the advantages of the Yocto solution for what I want?

My short-term goal is just to plug the package to the SBC and log temperature every x seconds into a text file. Possibly make the sensors accessible from the network but that's really not important since the SBC itself will be accessible through SSH. I am also interested in the YoctoBox-MaxilO-Transp, which may allow for better thermal accuracy given proper calibration of the thermistors (PT100 are a no-go for me, the sensor end is too big).

My longer term ambition is to make something more portable that could run on 2P or 4P 18650 batteries for several weeks (1 measurement/hour), and possibly transmit data using LoRaWAN to a gateway. However that will be more expensive due to the need for a "smart" hub, and it also seems much more difficult to achieve with both Yocto or Phidget solutions as they are not easy to implement with LoRaWAN (Yocto for instance chose GSM instead). In that specific case, maybe more DIY work with Arduino will be a better candidate for me. But that doesn't mean that I'm giving up on Yoctopuce for at least the first goal! Thanks in advance for your answer!

31 - mvuilleu (Yocto-Team)Tuesday,march 30,2021 13H07

@mtf We have never tried Phidget devices, but people in the Artisan roasting community use both and can certainly provide input. The main author of Artisan roasting software has published a comparison including both Yoctopuce and Phidget sensor precisions, see https://artisan-roasterscope.blogspot.com/2019/03/on-idle-noise.html

The ideal type of sensor depends on the required temperature range and reactivity, but maybe you should also consider thermistors, as they provide a very cost-effective of making multiple measurements, and measurement wires can easily be extended using normal wires. Our Yocto-MaxiThermistor has six inputs on a single device.

PT100 should also not be discarded too quickly just because of the probe size, as you can find tiny Pt100 inserts, see for instance https://www.labfacility.com/ceramic-sheathed-pt100-inserts.html . The absolute precision is definitely better than Thermocouple and Thermistors, but the price is also significantly higher...

Regarding LoRaWAN, we have made some preliminary studies but decided that this is not something we want to go forward with: bandwidth is too low for to accommodate our general use-cases, and country-specific regulations make it almost impossible to provide as a turn-key solution.

We have rather decided to focus on Wireless-n, NB-IoT and LTE-M for wireless communications. Our wireless YoctoHub feature a deep sleep feature that makes it possible to consume almost nothing during most of the time, and wake-up at predefined schedule to post data to a server just before returning to sleep. This makes it indeed possible to survive for several weeks on a 3500mA battery while posting one measurement per hour.

32 - mtf Tuesday,april 06,2021 17H07

Thanks for your quick answer mvuilleu.

Those PT100 tips are really interesting but I am afraid they might still be a bit too big for my use case, as I'm afraid the measurement in contact of the end may not be very reliable if the rest of the PT100 is exposed to air at a different temperature. Thermistors are definitely on my list though, I may end up buying a Phidget for thermocouples and some gear at Yocto for thermistors and compare both solutions. But the thermocouple equipment at Yocto is tempting too!

I haven't heard of NB IoT before, will look into it (but the choice of LoRaWAN is already made in my case and does not only depend on me). There are no Yocto chips using NB IoT on the store yet though I believe. Is there any rough ETA, and does NB IoT require some subscription like GSM? The advantage of LoRaWAN in my case if there's no third-party subscription required and nodes can be placed far from the gateway.

33 - mtf Wednesday,november 10,2021 16H10

I could not find in the manual any information on the size of the internal flash memory. I would like to know how much data (in terms of rows or at least file size) can safely be stored in the internal memory before it has to be emptied, and what happens when it is full (does it overwrite older rows, or does it stop?). Also, is the flash memory size the same on all Yoctopuce devices?

Regarding our discussion above and after some further investigation, I can confirm that Phidgets are cool devices. I received first so I wrote a little program to record/plot data with them from a headless computer while I was waiting for my Yoctopuce gear. I'm quite satisfied with them, but the use is more restricted since they do require a SBC or computer (I managed to make them work with my program on a Sailfish phone too, but still, they need a "brain"). By contrast, one significant strength of the Yoctopuce-thermocouples is they can also benefit from SBC for complex applications, but feature a datalogger funciton, whereby they can work autonomously when connected to a power source. They don't *require* a Yocto hub or a SBC. It is not clear however how much data they can store.

34 - martinm (Yocto-Team)Wednesday,november 10,2021 17H43

@mtf: On any device the datalogger can store at least 500'000 records. when the datalogger memory is full, the oldest records are overwritten. Exact flash memory size is displayed in the device logs at start up. Now we use 8MBytes chips, but early models had smaller memory. However depending on the firmware and device model some of the flash memory might also be used for other purposes, in that case the memory allocated to the datalogger is slightly smaller.

35 - mtf Thursday,november 11,2021 12H45

Thank you @martinm.

36 - lever Wednesday,june 28,2023 12H58

If I need to cut the included thermocouples to be shorter than the original 50cm, do I need to recalibrate the device?

37 - martinm (Yocto-Team)Wednesday,june 28,2023 12H59

@lever : nope.

Yoctopuce, get your stuff connected.