Part 2. Can be done at the river or at home / school
Equipment :
500ml water sample
12,880𝝻S/cm (High) Calibration Standard
Distilled water
Grey Electrical Conductivity Meter
Latex gloves
Safety glasses
Specimen container
1. With the EC meter in the calibration solution, press the ‘CAL’ button to put into calibrate mode – you will see the ‘CAL’ on screen followed by a default EC value.
Tip: Press ‘CAL’ button to exit Calibration Mode at any time.
2. Calibration mode is on when the ‘CAL’ symbol is on the screen.
3. The watch icon will stop blinking when the reading is stable and the icon will display on screen.
4. Ignore the numbers flashing across the bottom of the screen, and press ‘MENU’ button.
This will enable you to manually calibrate the meter.
5. Once the reading has stabilised again with the tick on screen, at the bottom a ‘Cond’ value will start flashing. To adjust to to the desired reading – 500 or what’s on your calibration solution bottle – press the MENU button until you reach the exact or closest number.
The adjustment will decrease only, but will eventually cycle up to the highest value and then decrease again (like an old alarm clock minutes).
6. Press ‘ENTER’ button to accept that ‘Cond’ number and finish the calibration when the desired value (500) is selected.
The display will show ‘done’ to confirm the manual calibration.
7. The meter is now calibrated and should read 500 on the screen.
If it doesn’t read 500 after calibrating, repeat the process.
8. Take the meter out of the solution, rinse EC meter probes with distilled water, and wash out the small beaker.
9. You can now continue on with your EC test on sample water, or turn off & put away if you’ll use it later for testing.
Pack Up
Rinse the probes in distilled water.
Blow on the probes or allow to dry in the air. - Important - Do not wipe the probes of the meter.
Replace the cap on the meter.
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Electrical Conductivity (EC) is the measure of the ability of water to conduct an electric current and depends upon the number of ions or charged particles in the water. EC is an indirect method of measuring salinity and includes the measurements of all salts and organic acids. Many species can only survive in a very narrow range of salt concentration.
The unit of measurement for electrical conductivity is expressed in either micro Siemens per centimetre (µS/cm) or milli Siemens per centimetre (mS/cm).