®
Flat pH Probe
Introduction
2
012-15716A
Preparation of the Electrode for Initial Use
1. Remove the storage bottle from the electrode and
thoroughly rinse the electrode with distilled water.
Wipe carefully with a clean lab wipe.
2. During shipment, air bubbles may have migrated
into the electrode sensing bulb. Hold the electrode
up to the light and inspect the sensing bulb for air
bubbles. If air is seen, carefully shake the electrode
downward (like a thermometer) to dispel the air
bubble from the sensing bulb at the tip of the
electrode.
Software Help
See the SPARKvue Help or PASCO Capstone Help for
information about collecting, displaying, and analyzing
data.
•
In SPARKvue, select the HELP button in any screen
including the Home Screen.
•
In PASCO Capstone, select PASCO Capstone Help
from the Help menu, or press F1.
Standardizing the Electrode
1. Connect your pH electrode to the input connector on
the Wireless pH Sensor (or other pH measuring
device). Ensure that the electrode connection is
secure.
2. Start the PASCO data collection software if you are
using a PASCO sensor. Connect the sensor to your
computing device (e.g., computer or tablet).
3. Start recording data. Place the electrode into a
beaker containing pH 7.00 buffer and a stir bar. Stir
at a moderate speed.
4. When the reading is stable, set the calibration value
in the software to match the value of the pH 7.00
buffer at the temperature in the laboratory.
5. Remove the electrode from the buffer. Rinse with
distilled water and blot with a lab wipe.
6. Place the electrode in a beaker containing pH 4.01
buffer and a stir bar. Stir as before. When the
reading is stable, set the calibration value in the soft
-
ware to match the value of the 4.01 buffer at the
temperature in the laboratory.
Reading a Sample with the Electrode
1. Rinse the electrode with distilled water and blot with
a lab wipe. Place the electrode in a beaker
containing the sample and a stir bar. The sam-ple
should be at the same temperature as the buffers
used to standard-ize the electrode. Stir as before.
Record the pH when the reading is sta-ble.
2. Remove the electrode from the sample, rinse the
electrode with distilled water over the "waste"
beaker. Blot the electrode dry with a lab wipe. The
electrode is now ready to read the pH of other
samples.
Storing the Electrode
Short Term
Between measurements, store the pH electrode in a
beaker containing pH 4.01 buffer.
Long Term
When storing for longer periods, store the pH electrode
in the storage bottle which came with the electrode.
Ensure that the foam in the storage bottle is totally
wetted with pH storage solution to keep a wet
environment around the pH bulb and junction. Maintain
the wet environment in the storage bottle boot during
storage.
Electrode Cleaning
Do not use strong solvents (e.g. acetone, carbon
tetrachloride, etc.) to clean the pH electrode. Be sure to
recalibrate the electrode after cleaning.
1. If the electrode has become coated with oil or
grease, carefully wash the electrode under warm tap
water using dish-washing detergent. Rinse
thoroughly with fresh tap water followed by a rinse
with distilled water. Soak the electrode in pH
electrode storage solution for 30 minutes after this
cleaning procedure. Recalibrate the electrode
before use.
2. If the electrode has been exposed to protein or
similar materials, soak in acidic pepsin for 5
minutes. Rinse thoroughly with distilled water. Soak
in storage solution for 30 minutes prior to
recalibration.
3. If the previous cleaning procedures fail to restore
response, soak the electrode in 0.1 N HCI for 30
minutes. Rinse thoroughly with distilled water.
Recalibrate before use.
