32
MW806
Portable Meter
9. EC / TDS
9.1. PREPARATION
Pour small quantities of conductivity calibration solution into
clean beakers. To minimize cross‑contamination, use two beakers:
one for rinsing the probe and the other for calibration.
Note: The TDS reading is automatically derived from the
EC reading and no TDS calibration is needed.
9.2. CALIBRATION
General Guidelines
For better accuracy, frequent calibration is recommended.
The probe should be calibrated:
y
Whenever it is replaced
y
After testing aggressive samples
y
When high accuracy is required
y
If “NO CAL” is displayed on the third LCD line
y
At least once a week
Before performing a calibration:
y
Inspect the probe for debris or blockages.
y
Always use an EC calibration standard that is close to the
sample. Selectable calibration points are 0.00 mS/cm for
offset and 1.41 mS/cm, 5.00 mS/cm, 12.88 mS/cm for slope.
To enter EC calibration:
1. Press RANGE/
to select EC measurement mode
("CONDUCTIVITy" displays briefly).
2. Press CAL/EDIT to enter calibration mode.
Zero Calibration
For zero calibration, to correct readings around 0.00 mS/cm,
keep the dry probe in the air. The slope is evaluated when the
calibration is performed in any other point.
μ
S/cm
ºC
ATC
mS/cm
CAL
25.1
0.0 0
0.00
W A I T
ACCEPT
μ
S/cm
ºC
ATC
mS/cm
CAL
25.1
0.0 0
0.00
S T D
