Measuring Salt - Chameleon EC meter

The Chameleon EC meter measures the Electrical Conductivity (EC) of the water sample captured by the Wetting Front Detector. It can also be used to measure the quality of the irrigation water. The EC measurement indicates the total amount of dissolved salts in the irrigation or soil water. These dissolved salts include fertilisers and harmful salts such as sodium chloride (NaCl). Since the EC of a solution is due to dissolved salts, measuring EC is often termed as a measurement of salinity. 

Range

The Chameleon EC meter has a range of 0.4 to 5.2 dS/m and the EC value of the water sample is displayed by 16 LEDs (lights). There are many different units for measuring EC and therefore some confusion about what the numbers mean. To keep things simple we have divided the 16 Lights into 4 groups as follows; 

  • Green 0.4 to 1.0 dS/m (low salinity)
  • Yellow 1.2 - 2.0 dS/m (low to medium salinity)
  • Orange 2.4 - 3.6 dS/m (medium to high salinity)
  • Red 4.0 to 5.2 dS/m (high salinity)

Instructions for use

The minimum sample size is 4 mL (The WFD usually captures a sample of 5 to 10 mL).

  1. Place the sample into the cap and replace firmly so that the metal probes are fully covered with the sample
  2. Wait at least 10 seconds for the temperature of meter and the water sample to equilibrate
  3. Remove cap and repeat above
  4. The LED will light up closest to the EC value on the meter
  5. If the reading is jumping between two values, then the EC is between those values
  6. If the reading is below 0.4 dS/m no light will come on (this represents very clean water)  

Maintenance

  • The probe should be cleaned after heavy use. Put alcohol in the cap and insert the metal probes. 
  • Replace the batteries if no lights appear when sample EC is greater than 0.4 dS/m.
  • The meter is powered by 3 x AA standard alkaline batteries.
  • Unscrew the battery cap at the top of the meter, remove old batteries and insert new batteries positive end down into the body.
  • Do not use rechargeable batteries.

Chameleon EC Meter

This video illustrates what is dissolved in soil water, why salt builds up in irrigated soils and how salts move in the ground water.