Similar to cars, pipettes need a tune-up every so often to ensure that they are accurate and working properly. Those who tend to wait until problems arise, often end up paying more for new pistons and shafts. Without regular preventive maintenance, most pipettes are subject to corrosion prior to going out of specifications, even though it may not be physically apparent.
Preventive maintenance involves inspection, disassembly and thorough cleaning of each pipette. The seal and o-ring are changed and the piston is lubricated if necessary. After recalibration the pipettes are like new. In order to maintain precision, in your measurements, a proper calibration and maintenance procedure should be performed on a regular basis. Usually pipettes are calibrated on an annual basis. You may require more frequent servicing of your pipettes. We suggest that you refer to your laboratories' Standard of Procedures (SOPs) and have them calibrated to align with your needs.