Calibration assure a pipette's accuracy by evaluating the quality of liquid dispensed at specific volume settings. A variety of factors, including the equipment used, qualifications of the personnel, laboratory environment and specific processes can affect the certainty of the measurements used when calibrating a pipette.

Pipette technicians calibrate pipettes by:
 

• Aspiring a defined quantity of de-ionized water
• Measuring it using state of the art analytical balances
• If necessary, making calibration adjustments and re-evaluating

 
The consistency of results or precision is calculated via a standard deviation. Expert technicians are able to maintain a very low standard deviation, therefore assuring their measurements are close to the expected value.

ISO 8655-6 recommends that every channel on a multichannel pipette be calibrated as if it were an individual pipette. We use METTLER TOLEDO MCP balances, which are specifically designed for multichannel pipettes and calibrate all channels simultaneously.

The time and hassles associated with internal and government audits means documentation is the only proof of compliance. The best type of documentation is a calibration certificate generated
by software, which is directly linked to the balance.

 
This software balance link is important as it restricts or even eliminates potential human intervention on reported results. Calibration certificates should specify the serial number of the pipette, date of the service, balance used, technician and more.