A solution designed specifically for the refill of liquid-containing pH probes. This liquid is also a storage solution.  Refill the probe, following the instructions supplied with the meter.  The probe should be topped up regularly to maintain correct levels.  This will ensure consistent readings.  The solution should not be used for refilling gel-based electrodes.  This liquid is also ideal for storage of all pH probes - the probe should stand in storage solution whenever it is not being used.  This will maximise accuracy and prolong the life of the electrode.