Hanna Instruments HI 93703 User Manual

Page 6

LOG

LOBAT

TIME

DATE

LOGGING

MICROPROCESSOR

TURBIDITY METER

LOGGING

MICROPROCESSOR

TURBIDITY METER

HI 93703-11

VIEW

STO

CLR

GLP

CAL

DATE

READ

ALT

OFF

188

FUNCTIONAL DESCRIPTION

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 read-

ing, and to view log memory

6) READ/DATE key, to perform measure-

ments, 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)

* 1 FTU = 1 NTU

STANDARD SUSPENSION
Presently, there are only two recognized pri-
mary 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 ob-
served.
On the other hand, formazine is a toxic sub-
stance, 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 es-
tablished by Advanced Polymer Systems and
Hanna Instruments.
Additional documentation about the formazine
standard and more complex calibration proce-
dures is available upon request.

• 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 ob-
jects 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") .