Hanna Instruments HI 4521 - Manual (Page 13)

13
CHANNEL SELECTION
• Press while in Measure mode to access channel
selection menu. Four available options will be displayed:
Channel 1, Channel 2, or multi-channel with the first or the
second channel focused. The “Choose Channel Configura-
tion” message is displayed in the Reminder messages area
when
is pressed.
• Select the desired option by pressing the appropriate key:
, , or . The instru-
ment will enter in the selected option Measure mode.
104
For AmpHel For AmpHel For AmpHel For AmpHel For AmpHel ® ® ® ® ® electrodes: electrodes: electrodes: electrodes: electrodes:
If the electrode does not respond to pH changes, the battery run down and the electrode should be replaced.
MEASURE
Rinse the pH electrode tip with distilled water. Immerse the tip (bottom 4 cm /1½”) in the sample and
stir gently for a few seconds.
For a faster response and to avoid cross-contamination of the samples, rinse the electrode tip with a few drops
of the solution to be tested, before taking measurements.
STORAGE PROCEDURE
To minimize clogging and assure a quick response time, the glass bulb and the junction of pH electrode should
be kept moist and not allowed to dry out.
Replace the solution in the protective cap with a few drops of
HI 70300 or HI 80300 Storage Solution or, in its
absence, Filling Solution ( HI 7071 or HI 8071 for single junction and HI 7082 or HI 8082 for double junction
electrodes). Follow the Preparation Procedure on page 103 before taking measurements.
Note: NEVER STORE THE ELECTRODE IN DISTILLED OR DEIONIZED WATER.
PERIODIC MAINTENANCE
Inspect the electrode and the cable. The cable used for connection to the instrument must be intact and there
must be no points of broken insulation on the cable or cracks on the electrode stem or bulb. Connectors must
be perfectly clean and dry. If any scratches or cracks are present, replace the electrode. Rinse off any salt
deposits with water.
pH Probe Maintenance
For refillable electrodes: For refillable electrodes: For refillable electrodes: For refillable electrodes: For refillable electrodes:
Refill the reference chamber with fresh electrolyte ( HI 7071 or HI 8071 for single junction or HI 7082 or
HI 8082 for double junction electrodes). Allow the electrode to stand upright for 1 hour. Follow the Storage
Procedure above.
pH CLEANING PROCEDURE
• General Soak in Hanna HI 7061 or HI 8061 General Cleaning Solution for approximately ½ hour.
• Protein Soak in Hanna HI 7073 or HI 8073 Protein Cleaning Solution for 15 minutes.
• Inorganic Soak in Hanna HI 7074 Inorganic Cleaning Solution for 15 minutes.
• Oil/grease Rinse with Hanna HI 7077 or HI 8077 Oil and Fat Cleaning Solution.
IMPORTANT: After performing any of the cleaning procedures, rinse the electrode thoroughly with distilled
water, refill the reference chamber with fresh electrolyte (not necessary for gel-filled electrodes) and soak the
electrode in
HI 70300 or HI 80300 Storage Solution for at least 1 hour before taking measurements.