Hach AutoCAT 9000, Instruction Manual

Page: 141 / 176

Maintenance
50081_Maintenance.fm
Page 139
Section 9 Maintenance
9.1 Instrument Maintenance
9.1.1 General
Protect the instrument from temperature extremes including direct sunlight, heaters, and
other heat sources. Do not store or use the instrument in a dusty, damp, or wet location.
9.1.2 Display
Do not scratch the display screen. Never use a pen, pencil, or other sharp object on the
display surface. The display is water-resistant, but should not be exposed to direct rain or
moisture. The display screen contains a glass element. Protect the screen against
strong impacts.
9.1.3 Cleaning the Instrument
Use a soft, damp cotton cloth to wipe the instrument and the display screen. If the surface
of the screen becomes soiled, cleaned it with a soft cloth and diluted window cleaning
solution. Do not use strong solvents.
9.1.4 Cleaning and Conditioning the Electrode
Clean and condition the AutoCAT 9000™ dual platinum electrodes (DPE) as shown in
the procedure below, to make them more responsive. The frequency of use and the type
of samples analyzed will dictate the frequency for electrode cleaning and conditioning.
Excess “noise” in the titration curve and/or poor curve shapes can indicate that the
electrode is dirty.
1.
Remove the plastic anti-
diffusion dispenser tip from
the electrode head and set
aside. See
Instrument
Assembly 6. on page 17 for
more information.
2.
Prepare a dilute nitric
acid solution. Measure
approximately 200 mL of
solution into a clean
250-mL beaker.
Note: Hach offers 1:1 (v/v)
Nitric Acid (Cat. No. 2540-49)
for electrode cleaning.
3.
Turn the instrument ON
or, if already in operation,
access the
Electrodes menu.
Note: The electrode cleaning
routine is identical for all
methods.
4.
Press
5
to select
Electrode Cleaning, and
follow the embedded
procedure.
After electrode cleaning is
complete, replace the plastic
anti-diffusion tip to the
electrode head.
Note: Electrodes should be
conditioned prior to first
running a titration. To condition
the electrode, soak in a dilute
chlorine solution.