Hanna Instruments HI 93124 User Manual

Page 6

• After approximately 30 seconds, the meter will

display “125”, asking for the 125 EBC solution
to be placed in the cuvette holder.

Note: At this point the user can exit the calibration mode and save the two-point

calibration by pressing ALT+CAL keys.

• To perform a three-point calibration, place a cuvette filled with HI 93124-2

standard solution (@ 125 EBC) in the cuvette holder.

• Press the CAL key. “SIP” and “CL” will start blinking.

• After approximately 30 seconds, the display

will show “----”.

Now the meter is calibrated and ready for use.

VIEWING CALIBRATION DATE

To display the last calibration time and date, press
the GLP button to toggle through date and time.

If the display shows "FS", the instrument has factory
calibration settings loaded and no date will be
displayed.

STANDARD SUSPENSION

Hanna Instruments supplies HI 93124 with the AMCO-AEPA-1 standards which
has a long shelf life at all concentrations (approximately six months, if free from
contamination). In addition, no special handling or disposal is required and a much
higher stability of suspended particles has been observed.

On the other hand, the formazine-based standards are very toxic, carcinogen and
unstable (particles flocculate and settle quickly). Lower concentrations change value
within a few days or hours after dilution from stock solutions.

The consistency of HI 93124 readings by using both standards has been separately
established by Advanced Polymer Systems and Hanna Instruments.

Additional documentation about the formazine standard and more complex
calibration procedures is available upon request.

CALIBRATION

If repeated measurements differ more than an acceptable value, check if the meter
calibration status by measuring a standard solution.
Anyway, it is recommended to perform a monthly calibration of the meter, or more
frequently for greatest accuracy.
To check the date of last calibration, simply press the GLP/CAL key. Press again to
toggle between date and time.

CALIBRATION PROCEDURE

• Turn the meter on and wait for the display to show

dashes “----”.

• Press ALT+CAL keys, the “CAL” message will blink on the display 3 times, then

the meter enter the calibration mode asking for the 0 EBC standard.

• Fill the measurement cuvette with HI 93124-0

standard (@ 0 EBC).

Note: In order to minimize any error introduced by the cuvette, it is recommended

to use the same cuvette during calibration and for measurements.

• Insert the cuvette with the 0 EBC standard solution (or turbidity-free dilution

water) into the measurement cell and press the CAL key. “SIP” and “CL” will
start blinking.

• After approximately 30 seconds the instrument

will ask for the 2.5 EBC standard solution.

• Repeat the same procedure with HI 93124-1 standard solution (@ 2.5 EBC):

fill the cuvette the HI 93124-1 standard, insert into the measurement cell and
press the CAL key again.