Aquamaster Calibration Fluids Storage and Cleaning – Calibration Solution

Frequently asked questions

• What Aquamaster solutions are available and what is each one for?

  There are four types with different functions: pH 4.01 and pH 7.00 to calibrate the pH meter, EC 1413 µS/cm as a conductivity reference standard, Cleaner D as a cleaning solution, and the KCl storage solution to preserve the electrode. Only the first three calibrate or verify; the other two take care of the probe.

• Can I calibrate pH with just one solution?

  No, you need both: pH 7.00 sets the electrode's zero point and pH 4.01 sets the slope. These are the two points of the standard calibration for any pH meter, and calibrating with just one leaves the adjustment half done.

• Why does my meter take so long to stabilize the reading?

  When a meter takes a long time to stabilize or simply won't calibrate, the cause is usually dirt on the electrode rather than a device fault. Cleaner D dissolves the film of salts, organic residue and biofilm on the bulb, and cleaning before calibrating resolves most of these cases.

• How should I store the electrode between uses?

  In the KCl storage solution, never in distilled water: pure water draws the ions out of the bulb and ruins it. A pH electrode's bulb must never be allowed to dry out, and proper storage is the difference between it lasting years or just months.

• Is the 5-liter size worth it for me?

  It depends on your usage. The 5-liter size is designed for facilities with several meters, in-line controllers or service workshops, where the cost per calibration drops significantly. If it's going to take you more than a year to use it up, it's not worth it, because the standard solution degrades once opened: the 100 ml bottle or the 20 ml single-dose sachets are a better choice.

• What best practices should I follow when calibrating?

  Never put the electrode directly into the bottle: pour the solution into a clean cup and discard the used solution without returning it to the bottle. Keep the liquids between 15 and 25 °C and with the cap tightly closed so the standard solution retains its value.