EC Meter

Hello,
I have been trying to make an EC Meter using arduino following the instructions from this website: https://www.instructables.com/id/Arduino-Water-Pollution-Monitor/
I tested the probe by making an LED glow but when it comes to the readings, I’m getting 5V or numbers very close to 5V for any liquid that I use. I’ve tried a number of different things to figure out what’s wrong but the end result is still the same. Could anyone help me with this?
Thank you.

Post details of your project (not the images in the link, images of YOUR project).

Which liquids did you try?

That's anyway a VERY crude EC sensor, will only give very rough results.

Came here from the instructable. Do you have any other recommendation for EC meter for accurate results?

Schematic is in the .cpp file of the library

I have improved versions of this board in development (EC + pH sensor; also have a few simple EC only boards on hand).

Thanks. The schematic is simple and good but I wanted a rugged waterproof solution so would be choosing EC Sensors from below

I want it to last a couple of years so above two seem perfect for me.

There is a whole KIT based EC Sensor as well ((Sensor & Kit) Soil Temp + Humidity + Electrical Conductivity EC Sensor Arduino | eBay) but I guess would be opting for above 2 to keep things small.

annleemrs1_4_198_9:
Wireless Water Quality sensor EC Electrical Conductivity Meter Arduino Compatibl | eBay

"not included: sensor probe".

Interestingly, the Instructable never shows the result of soldering stranded copper wire to nichrome wire. It is next to impossible to solder to nichrome wire because of the nickle and the chromium. You need to either use a crimp connector or spot weld the two wires together.

You will find you cannot use the sensor you make for an extended period of time without cleaning it.

Paul