Unless
an EC meter is ‘calibrated’, you cannot confidently use EC recommendations
i.e. like those supplied on many nutrient products. “Calibrating”
cross-checks the meter’s accuracy against a solution of known conductivity
called a “conductivity
standard”.
To calibrate, either refer to your meter's
instructions, or do the following:
Step 1.
Rinse electrode in distilled water then gently wipe with a tissue to
remove excess water. Immerse electrode in 2.76mS/cm (cF27.6)
Conductivity Standard* for 5 minutes, then calibrate (i.e. adjust) the
meter so that it reads the following:
+ For conductivity meters - calibrate to
2.76mS/cm or cF27.6.
+ For TDS meters - calibrate to 1800ppm (or
as directed).
*Note: To prevent contamination of the
stock solution, decant a portion into a smaller container and discard once
used.
Step 2.
Remove electrode from Conductivity Standard and rinse with distilled
water. The meter is now ready to be used.
