User Guide

15
* 1 FTU = 1 NTU
hours (the sample needs to be kept at room
temperature prior to the analysis).
• To obtain a representative sample, gently,
but thoroughly, mix it before samples are
taken. Do not shake (to prevent air bubbles)
and do not let the sample settle.
• It is recommended to calibrate the meter with
the supplied HI93703-10 @10 FTU* stan-
dard at least once a month or more frequently
for greater accuracy.
• Before inserting vials into the instrument,
wipe them with HI 93703-70 or a soft, lint-
free tissue. Handle vials so that no finger-
prints get on the areas where light passes
(approx. the bottom 2 cm/1 inch).
If you experience any problems in taking mea-
surements, contact your dealer or the nearest
Hanna Customer Service Center.
SOURCES OF INTERFERENCE
• Presence of floating debris and coarse sedi-
ments which settle out rapidly will give false
readings.
• The infrared light source used for HI 93703-
11 turbidity meter, complies with the ISO
7027 International Standard and can effec-
tively minimize any errors due to colored
dissolved substances. This effect, called
"true color", is a common interference for
most commercially available instruments
operating in the range of visible light.
• Air bubbles and the effect of vibrations that
disturb the surface of the sample may give
false results and should be avoided.
• Dirty glassware could also affect readings
along with scratched or dented vials.
16
To check the date of last calibration, simply
press the GLP/CAL key. Press again to
toggle between date and time.
To make sure that the meter is calibrated, take
a measure of a standard solution.
The instrument can be calibrated at two or three
points and a monthly calibration is recom-
mended.
CALIBRATION PROCEDURE
• Turn the meter on and
wait for the display to
show "----".
• Press the ALT & CAL
buttons together. The
"CAL" message will
blink on the display 3
times. The meter then
enters the calibration
mode, displaying "0.00
cl" and prompting the
user to insert the 0.00
FTU standard.
• Place the 0.00 FTU stan-
dard in the cuvet holder
• Press CAL, SIP and
CL will start blinking
LOGGING
MICROPROCESSOR
TURBIDITY METER
LOGGING
MICROPROCESSOR
TURBIDITY
METER
HI 93703-11
VIEW
STO
CLR
GLP
CAL
DATE
READ
ALT
OFF
ON
CALIBRATION
0.00
cl
sip
cl