hello everyone , I have a problem connecting pt-100 https://www.burkert.com/en/type/8417
the sensor has 4 ports
1- For ground
2-For power supply
3- For signal
4- empty

I want to get an analog input reading of the sensor From the device i am using which is called ETAS https://www.etas.com/en/products/es930_multi_io_module.php
and its analog input can only read voltage signals .

so how should i connect this sensor to get the right reading?

 

I couldn't find any details of the sensor output from that website. Do you have any details of this sensor output?

 

A PT100 sensor is basically a temperature dependent resistor that has a resistance of 100 ohms at 0deg C. Its resistance varies fairly linear with temperature at about 0.39ohms per degree C. So at +50deg C its resistance will be about 119.4 ohms.

Normally this is connected to a special analog input device that provides a current through the sensor to develop a voltage drop across it and this voltage is measured. Your device is a standard analog input and not really suited for the PT100 sensor.

If you connect the sensor in series with a 100ohm resistor and connect to a low voltage supply (5V or less), the voltage across the sensor can be measured. The supply voltage must be very stable or the reading will be affected. Because the resistance only changes slightly over its temperature range (-50C to +50C) using a standard analog input will only give a small range of voltages so the resolution will be quite low. Another thing to consider is that the current through the sensor will self-heat the sensor and affect its accuracy. A device designed to connect to a PT100 sensor uses various techniques to minimise this effect.

 

Normally this is connected to a special analog input device that provides a current through the device to develop a voltage drop across it and this voltage is measured. Your device is a standard analog input and not really suited for the PT100 sensor.

As this sensor apparently has a power supply connection presumably it has some circuitry inside it. If this is so then the output could be anything: digital signal; analogue voltage; 4-20mA; ...

 

I couldn't find any details of the sensor output from that website. Do you have any details of this sensor output?

unfortuntly me myself couldnt find the datasheet of it but their ports looks quite the same as the pressure sensor from the same company https://www.burkert.com/en/Media/pl...-ES-ES.pdf?id=MAN0000000000000001000109973ES-

 

A PT100 sensor is basically a temperature dependent resistor that has a resistance of 100 ohms at 0deg C. Its resistance varies fairly linear with temperature at about 0.39ohms per degree C. So at +50deg C its resistance will be about 119.4 ohms.

Normally this is connected to a special analog input device that provides a current through the device to develop a voltage drop across it and this voltage is measured. Your device is a standard analog input and not really suited for the PT100 sensor.

If you connect the sensor in series with a 100ohm resistor and connect to a low voltage supply (5V or less), the voltage across the sensor can be measured. The supply voltage must be very stable or the reading will be affected. Because the resistance only changes slightly over its temperature range (-50C to +50C) using a standard analog input will only give a small range of voltages so the resolution will be quite low. Another thing to consider is that the current through the sensor will self-heat the sensor and affect its accuracy. A device designed to connect to a PT100 sensor uses various techniques to minimise this effect.

i have tried to do it this way but it did not really work, do you think if i use Wheatstone bridge then it will work?
or is there some type of converters to use instead of building the circuit ?

 

unfortuntly me myself couldnt find the datasheet of it but their ports looks quite the same as the pressure sensor from the same company https://www.burkert.com/en/Media/pl...-ES-ES.pdf?id=MAN0000000000000001000109973ES-

Even though I can't understand the language of that data sheet I can see that this sensor uses a 4-20mA system. You need to be sure what system your sensor uses to be able to use it (and to avoid damaging it). Contact the manufacturer for a data sheet.

 

OK, if is 4-20mA then it will be easier to connect to your system. Get a full data sheet first!

If it is actually PT100 then you can use a module like this to convert to voltage or current:
http://www.farnell.com/datasheets/63960.pdf

 

As others have mentioned , PT100 RTD (resistor, temperature dependent) is a pretty standard temperature sensor. To use this device correctly you will need a suitable RTD converter. This will accept the RTD input and provide a suitable output. Usually 4-20mA. This can be fed through a 250 Ohm resistor to give a 1 to 5 volt signal. The convertor is usually powered by 24V dc.
You could make your own converter with a stable low volt supply feeding a bridge arrangement with the RTD in one leg and then amplifying the signal as required.

 

As others have mentioned , PT100 RTD (resistor, temperature dependent) is a pretty standard temperature sensor. To use this device correctly you will need a suitable RTD converter. This will accept the RTD input and provide a suitable output. Usually 4-20mA. This can be fed through a 250 Ohm resistor to give a 1 to 5 volt signal. The convertor is usually powered by 24V dc.
You could make your own converter with a stable low volt supply feeding a bridge arrangement with the RTD in one leg and then amplifying the signal as required.

could you please provide me with more information about how to make a convertor ?
i used this circuit https://www.ametherm.com/thermistor/ntc-thermistors-temperature-measurement-with-wheatstone-bridge
and i used 100 ohm for the 3 resistors and i got a voltage reading 2.5v

 

You need to find out whether what you have is a bare RTD or whether it has the converter already built-in.

 

You need to find out whether what you have is a bare RTD or whether it has the converter already built-in.

https://www.amazon.com/Icstation-PT...eywords=temperature+sensor+transmitter+module

do u think this one will solve the problem ?

 

It would be a good choice if your sensor is a bare RTD, but as your sensor apparently has a power input then it probably isn't a bare RTD and this module would be useless to you.

 

You need to contact the company and get more info on the device.
Guessing is not likely to solve your problem.