# How to read temperature using thermocouple

**URL:** <https://discourse.nodered.org/t/how-to-read-temperature-using-thermocouple/17306>\
**Category:** General\
**Created:** [30 October 2019 03:31 UTC](https://discourse.nodered.org/t/how-to-read-temperature-using-thermocouple/17306 "2019-10-30T03:31:04Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![madihatunn](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/madihatunn/32/13567_2.png) [@madihatunn](https://discourse.nodered.org/u/madihatunn)\
**Post date:** [30 October 2019 03:31 UTC](https://discourse.nodered.org/t/how-to-read-temperature-using-thermocouple/17306/1 "2019-10-30T03:31:04Z")

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Hallo, i want ask something. how to read temperature from thermocouple 4-20mA? i use modbus rtu protocol to this. output value from sensor in node red like the picture in bellow. how to fix it? thanks before guys

 ![image](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/2X/1/13ce8139988997f4e0459edfa9f07a256948cccf.png)

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**Author:** ![ukmoose](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/ukmoose/32/13_2.png) [@ukmoose](https://discourse.nodered.org/u/ukmoose)\
**Post date:** [30 October 2019 08:18 UTC](https://discourse.nodered.org/t/how-to-read-temperature-using-thermocouple/17306/2 "2019-10-30T08:18:47Z")

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Perhaps @Riky_maarif can help you as you both appear to be doing the same exercise with the same value [How to read Value Sensor from Modbus RTU](https://discourse.nodered.org/t/how-to-read-value-sensor-from-modbus-rtu/17274)

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**Author:** ![PaulKeates1](https://avatars.discourse-cdn.com/v4/letter/p/97f17d/32.png) [@PaulKeates1](https://discourse.nodered.org/u/PaulKeates1)\
**Post date:** [1 November 2019 21:20 UTC](https://discourse.nodered.org/t/how-to-read-temperature-using-thermocouple/17306/3 "2019-11-01T21:20:20Z")

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Depends on which ADC (Analogue Digital Converter) card / method you are using to read the values. MCP3008, others. Are there direct Node-RED nodes.

I use WidgetLords cards and have been very pleased (no affiliation) with direct support for Raspberry Pi and Node-RED. They have multiple 4-20 ma cards for IO.

Some cards will need additional resistors or other changes specifically to read thermocouples / thermistors.

Cheers,

Paul