Buying a conductivity meter for use in hydroponics

The following features are important considerations when choosing an EC meter

● Readout in Siemens (e.g. “mS”) or CF. Avoid meters that will only yield TDS (ppm).
● Calibration facility.
● A waterproof housing is desirable. However, this feature is generally not available on more sophisticated meters.
● Temperature compensation: A built-in temperature sensor and computer algorithm adjusts readings to display what the conductivity would be if the temperature was at 25OC / 77OF.
● Auto-off feature: For prolonging battery life.