Hello,
I am in the very early stages of building automated irrigation using arduino uno WiFi rev 2. I have acquired a Pt100 from work (probably overkill but it was free) that I wanted to use for reading outside temperature.
I purchased a 12vdc to O-5vdv voltage converter that I am hoping to use with the pt100 for analog signal to the arduino. Can anyone advice me on what I need to do in terms of writing code will I need to do any scaling or calibration? Thanks
Platinum sensors can be stable and precise, but their resistance variation is not big enough to measure (outside) temp with high enough resolution with an Arduino directly.
For that they must be paired with a digital processing board.
For outside temps a DS18B20 is a much cheaper/easier option than a PT100.
Leo..
You will need an amplifier board as Wawa has indicated. It will work great. The trick is to use them at a minimum of 3 wire configuration to maintain accuracy. If your sensor is 2 wires run 4 wires to the sensor then join RTD+ and F+ to one lead of the sensor, do the same with the negative leads. This will then automatically compensate for the lead resistance. There are a lot of online tutorials for using RTDs. Your PT100 is a 100 Ohm at 0C / 32F Platinum sensor.