Bluelab pH 4.0 Calibration Solution in a 250ml bottle is specifically designed for pH meters. Regular cleaning and calibration is required to improve the accuracy and lifespan of your Bluelab pH device. Calibration using reference standards of 4.0 and 7.0 pH is simple and the same for all Bluelab pH meters and pens.
After cleaning the pH probe, calibrate it with the calibration solutions to be able to carry out precise pH measurements again immediately. Repeat the calibration after cleaning the probe or when the device indicates a new calibration.