Turbidity sensor

what is the formula to get turbidity value in PPM? i want turbidity sensor to detect oil content in water..

ickulathunga:
what is the formula to get turbidity value in PPM? i want turbidity sensor to detect oil content in water..

Why do you believe there is such a formula?

Paul

If your sensor has a linear response: ppm = a * reading + b

a and b are obtained by calibration.

I am not a subject matter expert on this but I know that you can use TDS (Total Dissolved Solids) sensors instead of Turbidity sensors.

Quoting from

Many TDS meters display the TDS in parts per million (ppm); 1 ppm indicates 1 milligram of dissolved solids per kilogram of water.

TDS meters have voltage output which directly corresponds to parts per million or ppm unlike turbidity sensors.

Edit: found this TDS sensor that works directly with arduino: Arduino Analog TDS(Total Dissolved Solids) Sensor/Meter water quality ppm + Code | eBay

It has a ppm measurement range of 0 ~ 1000ppm

Turbidity and TDS are two completely different things.

And if that sensor has a range of just 0-1000 ppm it's useless for most real world applications.