LaMotte 2020t BLE Mode D'emploi page 47

number there would be no indication that a problem existed. For this reason, the 2020t/i
BLE displays negative numbers for turbidity.
„ TUBES AND CHAMBERS
The 2020t/i BLE uses specific tubes (Code 0260). These tubes have been annealed to
reduce irregularities in the glass. This reduces tube to tube variation and results in more
accurate readings. Only Code 0260 tubes should be used with this meter.
The handling of the tubes is of utmost importance. Tubes must be clean and free from lint,
fingerprints, dried spills and significant scratches, especially the central zone between the
bottom and the sample line.
Scratches, fingerprints and water droplets on the tube can cause stray light interference
leading to inaccurate results when measuring turbidity. Scratches and abrasions will affect
the accuracy of the readings. Tubes that have been scratched in the light zone through
excessive use should be discarded and replaced with new ones.
Tubes should always be washed on the inside and outside with mild detergent prior to use
to remove dirt or fingerprints. The tubes should be allowed to air-dry in an inverted position
to prevent dust from entering the tubes. Dry tubes should be stored with the caps on to
prevent contamination.
After a tube has been filled and capped, it should be held by the cap and the outside surface
should be wiped with a clean, lint-free absorbent cloth until it is dry and smudge-free.
Handling the tube only by the cap will avoid problems from fingerprints. Always set the clean
tube aside on a clean surface that will not contaminate the tube. It is imperative that the
tubes and light chamber be clean and dry. The outside of the tubes should be dried with a
clean, lint-free cloth or disposable wipe before they are placed in the meter chamber.
Tubes should be emptied and cleaned as soon as possible after reading a sample to prevent
deposition of particulates on the inside of the tubes. When highly accurate results are
required, reduce error by designating tubes to be used only for very low turbidity and very
high turbidity testing.
Variability in the geometry of the glassware and technique are the predominate cause of
variability in results. Slight variations in wall thickness and the diameter of the tubes may
lead to slight variations in the test results. To eliminate this error the tubes should be placed
in the chamber with the same orientation each time.
Chambers which have been scratched through excessive use should be discarded and
replaced with a new one.
MAINTENANCE
„ CLEANING
Clean the exterior housing with a damp, lint-free cloth. Do not allow water to enter the light
chamber or any other parts of the meter. To clean the light chamber and optics area, point
a can of compressed air into the light chamber and blow the pressurized air into the light
chamber. Use a cotton swab dampened with Windex
interior of the chamber. Do not use alcohol; it will leave a thin residue over the optics when
dry.
„ RETURNS
Should it be necessary to return the meter, pack the meter carefully in a suitable container
with adequate packing material. A return authorization number must be obtained from
LaMotte Company by calling 800-344-3100 (US only) or 410-778-3100, faxing 410-778-
6394, or emailing tech@lamotte.com. Often a problem can be resolved over the phone or
by email. If a return of the meter is necessary, attach a letter with the return authorization
number, meter serial number, a brief description of problem and contact information
including phone and FAX numbers to the shipping carton.
„ METER DISPOSAL
Waste Electrical and Electronic Equipment (WEEE)
Natural resources were used in the production of this equipment. This equipment may
contain materials that are hazardous to health and the environment. To avoid harm to
the environment and natural resources, the use of appropriate take-back systems is
recommended. The crossed out wheeled bin symbol on the meter encourages the use of
these systems when disposing of this equipment.
Take-back systems will allow the materials to be reused or recycled in a
way that will not harm the environment. For more information on approved
collection, reuse, and recycling systems contact local or regional waste
administration or recycling services.
window cleaner to gently swab the
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