6
The EC sensor of the SMEC300 sensor has an
internal constant that can be adjusted by the user
to correct for sensor drift. To calibrate the sensor,
you will need a container wide enough to accom-
modate the sensor and tall enough so the sensor
can be immersed to the midway point of the sen-
sor molding.
Sensor Preparation
Before starting the calibration procedure, the following pre-
liminary steps are necessary to ensure the sensor is properly
calibrated.
1. Because residual oils on the EC sensor pads, including oil
from your fingers, will reduce the accuracy of the sensor,
clean the sensor with rubbing alcohol. After cleaning the
sensor, do not touch the pads with your fingers.
2. Allow the calibration solution to come to room tempera-
ture. You must calibrate with a solution with an EC of
1.41 mS/cm. It is important for the sensor and solution to
be at the same temperature.
Calibration Procedure
1. Pour clean calibration solution into the container.
2. Plug the sensor into the reader.
3. Immerse the sensor in the calibrating solution up to sec-
ond mark on the molding. This ensures the sensor’s inter-
nal thermistor is below the liquid level. Take care that the
EC sensor pads are not touching the side of the container.
4. Set reader to CAL mode (see p.4).
5. Press and hold the SET button for 5 seconds. The LCD
will count down the time. When the calibration is com-
plete, the sensor will transition to Standard Spectrum
mode (see p.3). If the SET button is released before the
Calibrating the SMEC 300
EC Sensor
