Troubleshooting - Hach DR 1900 Manuel D'utilisation De Base

Clean the instrument
Clean the exterior of the instrument with a moist cloth and a mild soap solution and then wipe the
instrument dry as necessary.
Clean the cell compartment
Make sure there is no sample cell or cell adapter in the cell compartment before this task is started.
Turn the instrument and use a rubber suction bulb to blow carefully air into the cell compartment.
Clean the sample cells
Chemical exposure hazard. Obey laboratory safety procedures and wear all of the personal protective
equipment appropriate to the chemicals that are handled. Refer to the current safety data sheets
(MSDS/SDS) for safety protocols.
Chemical exposure hazard. Dispose of chemicals and wastes in accordance with local, regional and
national regulations.
Most laboratory detergents are used at recommended concentrations. Neutral detergents, such as
Liquinox, are safer to use when regular cleaning is necessary. To decrease the cleaning times,
increase the temperature or use an ultrasonic bath. To complete the cleaning, rinse a few times with
deionized water and then let the sample cell air dry.
Sample cells may also be cleaned with acid, followed by a thorough rinse with deionized water.
Note: Always use acid to clean sample cells that were used for low-level metal tests.
Special cleaning methods are necessary for individual procedures. When a brush is used to clean
sample cells, take extra care to avoid scratches on the interior surfaces of the sample cells.
Replace the batteries
Explosion hazard. Expired batteries can cause hydrogen gas buildup inside the instrument. Replace
the batteries before they expire and do not store the instrument for long periods with the batteries
installed.
Refer to Install the batteries

Troubleshooting

Problem
Absorbance > 3.5!
Over range!
Under range!
Reading Failed!
N O T I C E
C A U T I O N
C A U T I O N
W A R N I N G
on page 7 for battery replacement.
Possible cause
The measured absorbance is more than 3.5.
The concentration is more than the upper limit
of the current method.
The concentration is less than the lower limit of
the current method.
There is an electronic or optical defect.
Solution
Dilute the sample and repeat the
reading.
Dilute the sample and repeat the
reading.
Examine the sample.
Contact technical support.
English 15