pH 4.01 solution in 20ml sachet for calibration of electronic pH meters.

The pH meter is a precision instrument. Correct use and maintenance are important factors in getting the most out of your pH meter. Here are some important points to bear in mind:

- When purchased, the electrode is usually dried out. Soak it for 4 hours in the preservative solution. The cap you slide onto the electrode after use should be filled with preservative solution. This will preserve your electrode's functionality for a much longer period of time.

- Before taking a measurement, the pH indicator must be calibrated. Buffer solutions are used for this purpose. If your pH indicator can only be calibrated at one point, you should use the buffer solution that is closest to your normal measurements.

- Be careful not to introduce any "contamination" into the buffer solution. So never insert the electrode directly into the bottle, but pour a little solution into a beaker and use this for measurements. After calibration, discard the contents of any used cups and never re-introduce the liquid into the bottle!

- Never touch the electrode if you can avoid it, certainly not with your fingers. If you need to clean the electrode, use only a soft, non-scouring cloth.