pH buffer solution for the calibration of pH electrodes and pH instruments

pH Buffer Solution / pH Calibration Solution 

pH Buffer Solution is an item of significant importance when it comes to the initial setup and ongoing maintenance of a pH measurement or control solution.

Any new AWE Instruments pH controller will be factory calibrated to ensure that it is ready to receive the input from a pH electrode. Unlike other pH electrode manufacturers, each and every pH electrode is tested before it leaves the factory, so that your pH measurement and control solution is ready for operation.

The pH electrode will still need to be calibrated to the pH controller before it is put into operation.

This is done by using a pH Buffer Solution of a known value, with your pH electrode.

Our pH Buffer Solution is laboratory manufactured to ensure that the pH value at 25ºC corresponds to the given value.

The process for calibration is simple and documented within the operation and maintenance manuals, for each instrument we provide.

Normally a cleaned pH electrode is inserted into a vessel containing the pH Buffer Solution of known value. After a stabilisation period of no more than 25 minutes the value corresponding to the pH Buffer Solution is normally displayed on the screen. If the pH value displayed does not correspond to the value on the packaging then this can be adjusted via the zero and span settings to ensure that the correct value is displayed.

Normally when using a pH Buffer Solution, the first calibration solution used is a 7.00pH value.

The 7.00pH value should generate a signal corresponding to 0mV. If after the stabilisation period this value is not represented; then by adjusting the zero settings within the instrument you should be able to set the instrument to measure 7.00pH at this point.

Our instruments then use a 2 point, 3 point or 5 point pH calibration procedure.

A 2 point would use 7.00pH as the first calibration point and then a pH Buffer Solution relating to the measured process is normally used. A value of 4.00pH for acid applications then 9.00pH or 10.00pH is traditionally used where the measured value is on the alkali side of the pH scale.

A 3 point calibrated instrument would use a 7.00pH pH calibration solution and then a 4.00pH pH calibration solution and a 9.00pH or 10.00pH pH calibration solution.

pH critical applications use a 5 point calibration. Here, a starting point of 7.00 pH would then follow with 2.00pH, 4.00 pH, 9.00 pH, and 10.00pH rated calibration solutions are all used.

If the value on the instrument does not correlate with the pH Buffer Solution value, then normally, by adjusting the span setting, the instrument can be calibrated to the pH electrode in the pH Buffer Solution.

Certified pH Buffer Solution

Our pH Buffer Solution is available with certification showing that it complies and is certified to national standards, traceable to UK accreditation services.

Our certified pH Buffer Solution can be supplied with a free of charge Certificate of Conformity. This is normally to indicate that the pH Buffer Solution meets our most recent published specification. This is normally taken to mean that the pH Buffer Solution meets the specification printed on the label.

Our pH Buffer Solution can be supplied with a Certificate of Analysis. This gives the actual analytical results specific to the batch within which the pH Buffer Solution was produced. According to the amount of work involved during the batch analysis, we do have to charge for the supply of these certificates. Where the pH Calibration Solution requires supporting evidence that it is within the specification of supply, a Certificate of Conformity will normally suffice.

If you have a requirement for a Certificate of Analysis, normally at the bequest of an external audit or government agency, then we can certainly discus providing you with a pH Buffer Solution complete with Certificate of Analysis, traceable to national standards.

pH Buffer Solution Range


pHBS4 (4.00 pH buffer solution)

pHBS4 (4.00 pH buffer solution)

4pH buffer solution with model number pHBS4.

Supplied in containers ranging from 100ml through to 5 Litres and is available on our container return scheme.

The pHBS 4 can be supplied with a Certificate of Conformity for internal auditing purposes. We are also available to supply a 4.00 pH Buffer Solution complete with a full Certificate of Analysis for external auditing purposes.

View Product


pHBS7 (7.00 pH buffer solution)

pHBS7 (7.00 pH buffer solution)

7pH buffer solution with model number pHBS7

Supplied in containers ranging from 100ml through to 5 Litres and is available on our container return scheme.

The pHBS 7 can be supplied with a certificate of conformity for internal auditing purposes. We are also available to supply a 4.00 pH buffer solution complete with a full certificates of analysis for external auditing purposes.

View Product


pHBS9 (9.00 pH buffer solution)

pHBS9 (9.00 pH buffer solution)

9pH buffer solution with model number pHBS9

Supplied in containers ranging from 100ml through to 5 Litres and is available on our container return scheme.

The pHBS 9 can be supplied with a certificate of conformity for internal auditing purposes. We are also available to supply a 4.00 pH buffer solution complete with a full certificates of analysis for external auditing purposes.

View Product


pHBS10 (10.00 pH buffer solution)

pHBS10 (10.00 pH buffer solution)

10pH buffer solution with model number pHBS10

Supplied in containers ranging from 100ml through to 5 Litres and is available on our container return scheme.

The pHBS 10 can be supplied with a certificate of conformity for internal auditing purposes. We are also available to supply a 4.00 pH buffer solution complete with a full certificates of analysis for external auditing purposes.

View Product

Search