41
40
7. Probe Care and Maintenance
pH electrode care
Since your pH electrode is susceptible to dirt and contamination, clean it every one
to three months depending on the extent and condition of use. For specialty elec-
trode care, consult the instruction manual included with your electrode.
pH electrode storage
For best results, always keep the pH bulb wet. Use the protective electrode storage
bottle or rubber cap filled with electrode storage solution to store your electrode (see
page 46 for ordering information). Also, you can store in a pH 4 buffer with 1/100
part of saturated KCl. Other pH buffers are OK for storage, but NEVER use distilled
water for storage.
After measuring
1.
Rinse the pH electrode and reference junction in de-ionized water.
2.
Store the electrode as recommended above in “pH electrode storage,” or as
recommended by the manufacturer.
3.
Prior to next use, rinse the liquid junction with de-ionized water and tap dry—
never wipe electrode.
If this does not restore electrode to normal response, see
“Reactivating the pH electrode” section below.
pH electrode cleaning
Salt deposits:
dissolve the deposits by immersing the electrode in tap water for ten
to fifteen minutes. Ten thoroughly rinse with distilled water.
Oil/grease film:
wash electrode pH bulb gently in some detergent and water. Rinse
electrode tip with distilled water or use a general purpose electrode cleaner (see
page 40 for ordering information).
Clogged reference junction:
heat a diluted KCl solution to 60 to 80°C. Place the
sensing part of the electrode into the heated solution for about 10 minutes. Allow the
electrode to cool in some unheated KCl solution.
Protein deposits:
prepare a 1% pepsin solution in 0.1 M of HCl. Set the electrode in
the solution for five to ten minutes. Rinse the electrode with distilled water.
Reactivating the pH electrode
If stored and cleaned properly, your pH electrode should be ready for immediate
use. However, a dehydrated bulb may cause sluggish response. To rehydrate the
bulb, immerse the electrode in a pH 4 buffer solution for 10 to 30 minutes. If this
fails, the electrode requires activation. Never touch or rub glass bulb. Contact
builds up an electrostatic charge.
CONTINUED ON NEXT PAGE
7.1
Notes
To clear all pH data, see page 31.
See page 51 for a table of factory default settings.
P9.0: Resetting to factory default settings (conductivity/TDS)
This program lets you reset all conductivity parameters to factory default settings.
This clears all calibration data any other conductivity setup functions you might
have changed. The following settings will remain as you have set them:
• temperature unit of measure (°C or °F)
• The temperature offset calibration value
• All pH calibration data and parameters
MEAS
SETUP
mS
µ
S
ppt
ppm
A
MEAS
SETUP
MEAS
SETUP
mS
µ
S
mS
µ
S
ppt
ppm
ppt
ppm
B
6.10
From measurement mode
1.
Press the Mode key
to select
conductivity measurement mode.
2.
Press Setup key
to enter Set Up mode.
3.
Press the
▲
and
▼
keys
to scroll through
subgroups until you view parameter
“P5.0” in the lower display.
See figure
4.
Press the ENTER key
.
See figure
5.
Press the
▲
and
▼
keys
to toggle
between NO and YES.
• NO retains current settings
• YES resets to factory default settings
6.
Press the ENTER key
to confirm
selection and to return to measurement
mode.
A
B
