Ionode IJ pH User Manual

Page 2

Calibration

• Turn on the pH meter and connect the pH electrode and
temperature sensor (if available).
• Remove the wetting cap from the electrode and rinse the
electrode with distilled water.
• Perform a calibration by immersing the electrode in the ﬁ rst pH
buffer (pH 7.0 or 6.86), and stir. Adjust the reading when stable.
• Rinse the electrode and repeat the process with the second
pH buffer (usually pH 4.01 or 10.01).
• To check the calibration, recheck the 1st buffer value—the
reading should be within ± 0.02 pH of the buffer value. If not,
repeat the calibration.
• Rinse the electrode with distilled water or portions of the
sample to be measured.
• Buffers values should bracket the sample pH.

Helpful Hints

• Use the same technique during calibration and sample
measurements (including stirring rates).
• Try to ensure that the pH buffers and the samples are at
the same temperature (within ± 5C or better).
• Calibrate regularly and always use fresh buffers.
• Keep all connections dry.
• Use a dedicated high impedance pH meter.
• Immerse the electrode so that the reference junction is
below the surface.
• Do not use in ﬂ uoride solutions of low pH, as this will damage
the glass membrane.
• Minimise contact with sulphide vapours and change the
sleeve electrolyte frequently in these conditions.

Maintenance

• When not in use (short term storage), keep the electrode
immersed in 2-3M KCl solution to stabilise junction potentials.
• pH membranes are NOT damaged if allowed to dry. Ionode
pH glass usually rehydrates in under one hour.
• Replace sleeve electrolyte when necessary.
The frequency of this is best determined by experience,
however this should be done more often when measuring
contaminated samples.

Introduction

This guide contains the basic information for correct use
and maintenance of your new IJ44 pH electrode. A more
comprehensive manual is available for download from
www.ionode.com.au

Preparation

IJ44A/C electrodes are shipped without sleeve electrolyte,
and must be ﬁ lled prior to use. To ﬁ ll, hold the electrode
by the sleeve and gently ease off the rubber wetting cap.
Prepare as follows:

• For long term storage, remove and clean the sleeve.
Replace the sleeve (without electrolyte) and attach
the wetting cap.
• DO NOT store the electrode in deionized or distilled water.

Cleaning

Cleanliness of the sensor and junction is critical for
accurate measurement. Drift, poor slope and slow
response are often due to an unclean sensor/junction.
Clean the electrode periodically. Remove the sleeve
and clean the membrane, ground glass stem and
sleeve using one of the following methods.
Do not use abrasive materials.

Method One: Alkaline samples and scale: Soak
membrane in 1M HCl for an hour. Wash well with
water and condition in 20% KCl before use.

Method Two: Grease and oil: Wipe the membrane
and ground stem with cotton or tissue soaked in
acetone followed by methylated spirits. Wash with
distilled water before use.

Method Three: Solids and organics: Wipe the membrane
and junction with cotton or tissue soaked in a mild
non-alkaline detergent. Wash with distilled water and
condition in 20% KCl before before use.

Method Four: Strongly adsorbed and chemically
bonded impurities: Remove with non-abrasive
cleaner such as Jif.

Use undiluted on a soft cloth

and scrub the membrane well. Wash well with water
and condition in 20% KCl before use.

Method Five: Protein contamination: Soak electrode
in 1% Pepsin solution in 0.1M HCl for 15 minutes,
followed by rinsing with distilled water.
Finally, condition in 20% KCl before use.

Fill the annular space with gel

or electrolyte to approximately

half to three quarter full.

Slide the sleeve back onto the electrode ensuring the

black O-ring is well seated within the electrode body.
Do not exert sideways force. Any excess electrolyte will be
expelled from the end of the electrode through the ground
junction. Ensure there are no air bubbles in the sleeve.

With the pH bulb facing downwards, gently ﬂ ick the electrode

to remove any bubbles from within the membrane.Wash off
any excess electrolyte and store in 2-3M KCl before use.

www.ionode.com.au

Invert the electrode. Hold the

electrode just below the sleeve

and with careful rotation and

pulling along the axis of the

electrode, remove the sleeve.

DO NOT BEND.