Changes in temperature affect a pH reading. This is why you will usually see the temperature printed on the side of the bottle of pH buffer solutions. The buffer will be closest to its stated pH at that temperature (usually 20^oC or 25^oC)

When calibrating a pH meter with automatic buffer recognition, it is recommended to use the correct buffer. So please check the manufacture’s instructions to see which ones they suggest, i.e. 20^oC or 25^oC. It can make a difference to the calibration slope or how quickly the meter stabilizes.

To make the purchased of buffer solution easy, we have listed a range of 20^oC and 25^oC pH buffers below, with a link to the relevant webpages.

25^oC Buffers

• 1145585 – Buffer Solution pH4.00 (Red) ± 0.010 @ 25°C 500ml          
• 1145586 – Buffer Solution pH7.00 (Yellow) ± 0.010 @ 25°C 500ml     
• 1145550 – Buffer Solution pH10.00 (Blue) ± 0.010 @ 25°C 500ml       

20^oC Buffers

• 1144885 – Buffer Solution pH4.00 (Red) ± 0.01 @ 20°C 500ml
• 1144955 – Buffer Solution pH7.00 (Yellow) ± 0.01 @ 20°C 500ml
• 1145008 – Buffer Solution pH10.00 (Blue) ± 0.01 @ 20°C 500ml

Please note the manufacturer instructions for storage of your pH probe.

Usually, they need to be kept in a storage solution. If the pH probe dries out, it may become damaged and not give you accurate results. Why not purchase some TrueScience storage solution too?

• 1206841 – pH Electrode Storage Solution 250ml                  

For further information on pH, please consult our Product Guides section on:

• What is pH, and how is it measured?
• Choosing the right pH meter and electrode for the job
• How to take a pH reading and recommended electrode maintenance

Along with numerous blogs, we have produced on the subject of pH.