Temperature and water level sensor

I am trying to connect my Arduino nano to a Chinese temperature and water level sensor.
This sensor has only 2 wires. so i am unable to figure out how to get the temperature and the level sensor out of these 2 wires.
What puzzled me is how to get two readings through just 2 wires ?

What does the documentation say?

Paul

unfortunately i have no documentation or datasheet

If you have no documentation, why do you think it is a temperature and water level sensor?

It's already installed on my solar water heater. and it's available on aliexpress and ebay and marketed as "2 Cores temperature and water level sensor"

Looks like each of the 2 'wires' you see have 2 conductors in each!

missdrew:
Looks like each of the 2 'wires' you see have 2 conductors in each!

Thermocouple wires are extremely small so they have little effect on the junction of the thermocouple itself. They likely used the same wires for the other sensor.
Paul

yes that's obvious. but how it's connected. i mean how to read the data of both sensors ?

Ask the manufacturer for the details.

You will get only guesses on this forum, because we have no information either.

samkab:
yes that's obvious. but how it's connected. i mean how to read the data of both sensors ?

Use you Ohmeter. Measure the resistance of one pair. Hold one part of the sensor in your hand to warm it. If the resistance changes, that means the it is the temperature sensor. If it is truly a thermocouple, then you will need an amplifier. If your DVM has a thermocouple connection, try it. Then see if you can measure the millivolts generated by the sensor. If you can see a reading while warming the sensor, then it is truly a thermocouple. If no voltage is read, you have thermistor sensor. Write down for permanent reference the resistance you see when the device is cold..
For the second sensor wires, you may have a strain sensor that reflects the bending of the sensor caused by the floating end of the sensor pair. Using your Ohmeter, see if you get changes in resistance as you flex the sensor at the bending location.
All of the above are best guesses!!!
Paul

I believe you are right. a voltage rising proportional to the temperature is detected. so as you said it's a thermocouple. regarding the level sensor, the resistance between two wires is around 5M. applying pressure to the sensor has only a very small effect on the resistance.
i will give it more tests and post the resutls.
thank you for the hint