TDS Meter (Allison Shiff)

Author Allison Shiff

Nobel Middle School

Sensor / Probe: TDS (Total Dissolved Solids) Water Quality Meter

• • 1. A TDS Meter indicates the Total Dissolved Solids (TDS) of a solution, i.e. the concentration of dissolved solids in it. Since dissolved ionized solids such as salts and minerals increase the conductivity of a solution, a TDS meter measures the conductivity of the solution and estimates the TDS from that. This probe is also used for measuring dissolved solids for water purity.

Sample Investigation:

My students designed various water filters from some basic supplies. They used a water bottle to construct the frame. They layered the following items cotton, sand, filter paper and gravel. They chose how big each layer was and in which order the layers were arranged. As this was an engineering class called "How Things Work" they had 2 testing and modifications before final testing with the probe. The goal was to successfully lower the TDS number with each successive revision of their design. I used the guide on the sensor as a general target for where their numbers should be.

Sample Data & Analysis and Interpretation

Photos and Movie

This is the Water Purifier that my students made

This is the TDS reading of the "Dirty" water

This is the TDS reading AFTER it went through the purifier