HI 93703-11

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FUNCTIONAL DESCRIPTION

1

2

3

4

LOG

HI 93703-11

188

DATE %

TIME

LOBAT

ON

OFF

LOGGING

MICROPROCESSOR

TURBIDITY METER

5

6

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1) Measurement cell

2) LCD (Liquid Crystal Display)

3) ON/OFF/CLR key, to turn the meter ON and OFF, and to clear log memory

4) GLP/CAL key, to display last calibration date & time, and to enter calibration mode

5) STO/VIEW key, to store sample after reading, and to view log memory

6) READ/DATE key, to perform measurements, and to display (toggle) current date/time

7) ALT key, to activate the second functions

(second function keys in orange)

8) RS232 connector (5 pin)

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• All glassware that comes into contact with standards should be maintained clean. Wash with the HI 93703-50 cleaning solution and rinse with HI 93703-0 or turbidity free water.

• Rinse the vial twice with 5 ml of the liquid to be tested. This removes the effect of any previous liquid and any dust or foreign objects that may be present inside. Gently pour the liquid down the side of the vial to reduce air bubbles (no mixing is required when HI

93703-0 and HI 93703-10 AMCO-AEPA-1 standards are used).

• Before inserting the vial into the instrument, wipe it with HI 93703-70 or a soft, lint-free tissue. Handle vials so that no fingerprints can get on the areas where light passes

(approx. bottom 2 cm/1") .

STANDARD SUSPENSION

Presently, there are only two recognized primary standards: AMCO-AEPA-1 and formazine.

Hanna supplies HI 93703-11 with the AMCO-

AEPA-1 which has a much longer shelf life at all concentrations (approx. 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, formazine is a toxic substance, generated by a known carcinogen, with poor stability (particles flocculate and settle quickly). Lower concentrations change value within a few days or hours after dilution.

The consistency of HI 93703-11 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.

* 1 FTU = 1 NTU

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