The Bluelab pH 4.0 Calibration Solution in 500 ml size is specially designed for pH meters. With this solution you can improve the accuracy and lifespan of your Bluelab pH device. Calibration is easy to perform and applies to all Bluelab pH meters and pens.
After cleaning the pH probe, it is important to calibrate it with the calibration solutions at the reference standards 4.0 and 7.0 pH. You can then measure the pH value again immediately. Regular calibration is necessary after you have cleaned the probe or the meter indicates a calibration.