Hach PHC725, User Manual

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3.3 Precautionary labels
Read all labels and tags attached to the instrument. Personal injury or damage to the instrument
could occur if not observed. A symbol on the instrument is referenced in the manual with a
precautionary statement.
Electrical equipment marked with this symbol may not be disposed of in European
domestic or public disposal systems. Return old or end-of-life equipment to the
manufacturer for disposal at no charge to the user.
3.4 Product hazards
C A U T I O N
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.
C A U T I O N
Chemical exposure hazard. Dispose of chemicals and wastes in accordance with local,
regional and national regulations.
C A U T I O N
Personal injury hazard. Glass components can break. Handle with care to prevent cuts.
Section 4 Preparation for use
N O T I C E
Make sure to remove the protective tape from the filling hole of new probes. A probe with a blocked
filling hole will not operate correctly.
New probes are filled with electrolyte filling solution and have a soaker bottle that contains storage
solution to keep the glass bulb and reference junction hydrated. Prepare the probe for calibration and
measurement as follows.
1. Remove the protective tape from the filling hole. Refer to Figure 2 .
Note: Put the soaker bottle on the soaker bottle holder when not in use.
2. Rinse the reference junction and glass bulb with deionized water. Blot dry with a lint-free cloth.
3. If the inner filling solution is low, add more filling solution. Refer to Fill the probe on page 12.
4. If the level of KCl crystals in the probe is less than approximately 0.5 cm (0.2 in.), or for
measurements at high temperatures (> 60 °C (140 °F), add more KCl crystals. Refer to
Add KCl
crystals to the probe on page 13.
5. Invert the probe to make sure that the KCl crystals move freely through the liquid. If necessary,
shake the probe to loosen the crystals.
6. Soak the probe in a warm pH 4 buffer solution for approximately 1 hour to condition the probe.
Note: If probe stabilization is slow, soak the probe for 2 hours in a warm pH 4 buffer solution. The soak
procedure helps to dissolve KCl crystals in the reference junction.
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