10
ERROR MESSAGES
a) on zero reading
This indicates that the zeroing procedure failed due to a low signal-
to-noise ratio. In this case press ZERO again.
“No Light”: the instrument cannot adjust the light level. Please check
that the sample does not contain any debris.
“Light Low”: there is not enough light to perform a measurement.
Please check the preparation of the zero cuvet.
“Light High”: there is too much light to perform a measurement.
Please check the preparation of the zero cuvet.
b) on sample reading
There is too much light for the sample measurement. Please check
if the right sample cuvet is inserted.
“Inverted”: the sample and the zero cuvet are inverted.
“Zero”: a zero reading was not taken. Follow the instruction in
the
measurement procedure
for zeroing the meter.
Under range. A blinking "0.00" indicates that the sample absorbs
less light than the zero reference. Check the procedure and make
sure you use the same cuvet for reference (zero) and measurement.
A flashing value of the maximum concentration indicates an
over range condition. The concentration of the sample is beyond
the programmed range: dilute the sample and re-run the test.
A flashing value lower than the maximum concentration indicates
a low signal-to-noise ratio condition. In this case accuracy of the
result is not guaranteed. Repeat the
measurement procedure
.
11
The instructions listed below should be carefully followed during testing to ensure best accuracy.
class A pipette
• For adding the exact amount of sample and deionized water to
the cuvet it is strongly recommended to use two class A
laboratory pipettes.
• Alternatively, fill the cuvet up to the 10 mL mark: the liquid in
the cuvet forms a convexity on the top; the bottom of this
convexity must be at the same level of the 10 mL mark.
• For dosing the reagent, we recommend to use the supplied
Hanna HI 731342 automatic pipette.
For a correct use of the Hanna automatic pipette, please follow
the related Instruction Sheet.
• Color or suspended matter in large amounts may cause
interference, therefore these should be removed by treatment
with active carbon and by prior distillation.
• It is important that the sample does not contain any debris.
This would corrupt the reading.
• In order to avoid reagent leaking and to obtain more accurate
measurements, it is recommended to close the cuvet first with
the supplied HDPE plastic stopper
and then
with the black cap.
• Each time the cuvet is used, the cap must be tightened to the
same degree.
• Whenever the cuvet is placed into the measurement cell, it
must be dry outside, and completely free of fingerprints, oil or
dirt. Wipe it thoroughly with
HI 731318
(tissue for wiping
cuvets, see chapter ACCESSORIES) or a lint-free cloth prior to
insertion.
GENERAL TIPS FOR AN ACCURATE MEASUREMENT
Hanna
automatic pipette
