TDS Meters

TDS Meters

Simply Hydroponics and Organics carries a complete line of Total Dissolved Solids (TDS), CF and EC (electrical conductivity) meters. We have divided them into two different categories: Hand-held (portable) and Continuous Monitoring. There are also Combination Meters that read both TDS and pH eliminating the need for two separate meters.

There is some confusion about the difference between EC meters, CF meters and TDS meters. All these meters measure the exact same thing; electrical conductivity. The difference between them is the way the information is presented. 

An EC meter is a direct reading of the electrical conductivity of the solution stated in mS/cm. 

A CF meter presents a reading in µS/cm. The CF reading will be 10 times greater than an EC reading (example: an EC reading of 1.4 will be a CF reading of 14).

For some reason the American public doesn't like either of these two readings, (probably because they are metric measurements). For the American market the manufacturers have come up with a different plan, they have made their devices display measurements in a PPM (parts per million) scale and these are generally referred to as TDS meters. These TDS meters are actually EC meters with a conversion factor that changes the display from EC to a theoretical PPM value. The real confusing thing is that each manufacturer uses a different conversion factor which means that properly calibrated meters from different manufacturers will display a different PPM for the exact same liquid. The difference isn't great nor is it a problem. It simply means that the TDS meters are generally less accurate than an EC meter.