integrate an Infrared contact-less pyrometer

QuentinLe

Hello ,
For one of our special project we are trying to integrate an Infrared contact-less pyrometer or temperature sensor.
We are trying to measure a substrate that should vary between 15°C and 150°C and for this the pyrometre should be capable of reading let's say from -50°C to 300°C.
+/-2°C precision is not a big issue for us.

We are using a Duet3D 6HC main board. No daughter boards and we would like to avoid adding a board just for this.
Many type of sensors exist with different output possibilities:
UART
I2C
Analog voltage (mainly 0-5V or 0-10V)
4-20mA (Current loop)
Thermocouple type output for some (K/J)

I undestand this topic has been treated before
https://forum.duet3d.com/topic/29639/contact-less-infrared-temperature-sensor-mlx90614
https://forum.duet3d.com/topic/28845/pir-pyrometer-sensor-as-temperature-sensor-for-liquid/6?=1680777925024
https://forum.duet3d.com/topic/7681/i2c-pyrometer-module-as-temperature-sensor/4?=1680854551896
But those are old now and I believe some updates have been integrated to Duet since.

Under sensor type for M308 command we can now find the following.
"thermistor", "pt1000", "rtd-max31865", "thermocouple-max31855", "thermocouple-max31856", "linear-analog", "dht21", "dht22", "dht-humidity", "bme280", "bme-pressure", "bme-humidity", "current-loop-pyro", "drivers", "mcu-temp"

1- would a 4-20mA output capable sensor work with "current-loop-pyro"? Where should we connect it? to tempx connectors? any polarities to respect?
2- If we go with an analog output sensor, what should we chose, 0-5V or 0-10V or even 0-50V, and why? How would the ADC know the "full scale" (sorry for my little knowledge in electronics)
3- I have read that I/O1 and I/O2 are now UART capable, we have no panel due but endstops connected there. Can you explain to us the correct way of cabling and programing a sensor there if we chose to go with an UART one?
4- what are your recommendations in terms of reliability, which type of sensors are more prone to noise...

Your help and clarifications are appreciated.

Some sensors we are thinking about:
https://docs.rs-online.com/1fd1/A700000008530366.pdf
https://docs.rs-online.com/cb45/0900766b81344af0.pdf

T3P3Tony

@QuentinLe said in integrate an Infrared contact-less pyrometer:

Thermocouple type output for some (K/J)

that with a thermocouple daughterboard would be the simplest

QuentinLe

Hello @T3P3Tony

What about current-loop-pyro ? Did you know what about it ?

Thanks for your reply.

T3P3Tony

@QuentinLe that would be possible but requires some extra hardware to interface with the duet.

dc42

@QuentinLe said in integrate an Infrared contact-less pyrometer:

What about current-loop-pyro ? Did you know what about it ?

That was a special daughter board that we made for an OEM. The original pyro we used with it was a 2-terminal device that just needed about 12V, which meant we were able to connect it between +12V and the top end of a sense resistor, with the bottom end of the sense resistor grounded. We used an ADC to measure the voltage across the sense resistor, and the current-loop-pyro option in RRF talks to that ADC over SPI.

There are other types of current loop pyro sensors around that are not 2-terminal. Interfacing to those would require the use of a digital isolator, to isolate the ADC chip from the Duet.

koubz

@dc42

@dc42
hello ,

I'm also interested by this same topic.

So what is the easiest solution to integrate today one of these sensors on a 6HC board?

If i understand correctly "current-loop-pyro" was a special dev and it is not supported by 6HC unless why buy the special board.

What about sensors that give a 0-10V signal as output, using them with "linear analog" would work?

What about UART or even thermocouples output ones?