How Are The Accuracy And Precision Of A Pipette Pump Calibrated?

The accuracy and precision of a pipette pump are crucial factors in ensuring reliable and precise liquid handling in laboratory settings. Calibration is the process by which the accuracy and precision of a pipette pump are determined and adjusted if necessary. Here is an explanation of how the accuracy and precision of a pipette pump are calibrated:

1. Calibration Standards: Pipette pump calibration involves comparing the delivered volume of the pipette pump to known reference standards. These reference standards have been accurately calibrated and have known volumes. The calibration process aims to establish accurate and traceable calibration values for the pipette pump.

2. Calibration Procedure: The calibration procedure typically involves measuring the delivered volume of the pipette pump at various predetermined settings or volumes. A series of measurements are performed using the pipette pump, and the delivered volumes are compared to the reference standards. The deviations or differences between the measured values and the expected values are recorded.

3. Adjustment and Correction: If deviations or differences are detected during calibration, adjustments can be made to correct the error. This adjustment process may involve fine-tuning the internal mechanisms or recalibrating specific components of the pipette pump. The goal is to bring the delivered volumes of the pipette pump within an acceptable range of the expected values.

4. Calibration Tools and Equipment: Calibration of pipette pumps requires the use of specialized tools and equipment. These may include precision balances, gravimetric methods, volumetric flasks, or other calibrated measuring devices. The calibration equipment should have a higher level of accuracy and precision than the pipette pump being calibrated to ensure reliable results.

5. Calibration Certificates: Once the calibration process is completed, a calibration certificate is provided. This certificate indicates the accuracy and precision of the pipette pump at specific volumes or settings. It serves as proof that the pipette pump has been calibrated and helps establish traceability and compliance with quality standards.

6. Manufacturer Calibration: Pipette pump manufacturers typically perform initial calibrations on their products before they are shipped to customers. The manufacturer's calibration process ensures that the pipette pumps meet the specified accuracy and precision requirements. This initial calibration serves as a baseline, and subsequent calibrations by the user aim to maintain and verify the instrument's performance.

7. Calibration Intervals: The frequency of calibration depends on various factors such as the frequency of use, the criticality of the application, and regulatory requirements. Regular calibration is necessary to detect and correct any drift or deviations in the pipette pump's performance. Manufacturers and regulatory guidelines often provide recommendations on calibration intervals.

8. Traceability and Compliance: Calibration processes for pipette pumps adhere to international standards and guidelines, such as ISO 8655, which define the requirements for accuracy, precision, and calibration of liquid handling instruments. Compliance with these standards ensures traceability and comparability of results across different laboratories.

In conclusion, the accuracy and precision of a pipette pump are calibrated by comparing the delivered volumes to known reference standards through a systematic calibration procedure. The calibration process involves adjustments if necessary to correct any deviations. Calibration certificates provide evidence of the instrument's calibration and serve as a record of traceability. Regular calibration is essential to maintain accurate and precise liquid handling, and compliance with international standards ensures reliable performance.