PPM Meters - RO water

Can anyone provide a link of a PPM meter that can be used with RO water? Also of anyone can share why regular meters can be used with RO water. Thanks

Never heard it said that a ppm meter cant be used with RO water.
Just buy a quality meter like a blue lab. Avoid cheap crap on amazon.

they can all be used with ro water....they measure the conductivity of dissolved solids in the water, makes no difference whether the water has undergone reverse osmosis or not

I simply use an inline meter on the delivery line to my storage tank...
When that reads over 50ppm while running freshly filtered. Time to change filters.

I've ran across that information a few times and I didn't understand it. Thanks for clearing that up!