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From the “Calibration” menu select “Single param. calibration” and then “Turbidity calibration”.
The display shows two options: “Calibrate turbidity” and
“Restore factory calib”.
The Hanna Instruments turbidity sensor conforms to ISO 7027
standards which specifies the angle between the emitted and
detected light and the light source wavelength. For best results
perform a three point calibration at 0.0, 20.0 and 200.0 FNU. Although the basis of calibration for
this measurement is the standard Formazin, from a practical point of view, these standards require
daily preparation. A secondary standard based upon polystyrene beads is a more practical approach.
See Accessories for information regarding Hanna Instruments calibration solutions.
Note: Turbidity standard formulations made with polystyrene beads are instrument specific and
cannot be swapped with standards made for another turbidity sensor model.
Verify the sensor is clean before calibrating. The use of the HI7698293 calibration beaker is required
for this procedure.
Calibration is required every time the sensor is replaced and is recommended to be part of yearly
validation of your system.
Preparation
Pour quantities of selected standard solutions into clean beakers for rinse. Fill the HI7698293
calibration beaker with the zero standard. Submerse the turbidity sensor into zero rinse beaker and
then shake off excess solution. Place the sensor into the calibration beaker. It is extremely important
that no bubbles are present on the optical area. Gentle agitation of sensor or beaker may be required
to dislodge bubbles before screwing the beaker on fully.
Note: These procedures calibrate the slope value.
To calibrate the offset, set the calibration point at
0 µS/cm and repeat the procedure. If the temperature
input is not within the acceptable range (0 to 50 °C),
the message “Invalid temperature” is displayed.
If the conductivity input is not within the acceptable
range, the message “Wrong standard” is displayed.
TURBIDITY CALIBRATION
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