Tips on Getting the Most Out of Your Calibration Services
Pam Wright of the American Association for Laboratory Accreditation (A2LA) published a guide on navigating calibration services in the most recent issue of Cal Lab: The International Journal of Metrology. Here, we provide a summary of A2LA’s insights to help readers understand how best to ensure good scientific outcomes that depend on pipette calibration.

How to Select a Calibration Service

The process for choosing a calibration service is similar to that of any large purchase. Specifically, it is important to research different services and compare the options. Speaking directly with the calibration provider can help ensure that you will receive the specific services you need. Wright points out that speaking with a metrologist or other technical employee may be more beneficial than speaking with sales staff for obtaining precise information about the calibration services, for instance, is the provider accredited to both ISO 17025 and ISO 8655 (click here to see why ISO 8655 is important) Though cost is an often an important consideration in the selection of a calibration service, funds will be wasted if the service does not meet your specific requirements. (Read more about controlling pipetting costs here.) You should therefore balance cost with the rigor of calibration and traceability when making your final selection for your calibration service.

How to Place Calibration Orders

Often, only a partial calibration will be performed unless you specifically request that the full specification be used to evaluate your equipment. The more specific the information you provide about your equipment, how you use it, and any accreditations required, the more likely the service is to be accurately matched to your needs. For example, even though a provider may be accredited, don’t assume that they will automatically provide you with their accredited services. To ensure you are getting the most value out of your calibration services, you should make a habit of asking that your equipment be returned with an accreditation certificate that includes the accreditation symbol, the accreditation certificate number, the measurement data from the calibration, any measurement uncertainty, and the calibration interval.

How to Evaluate Your Calibrated Equipment

To properly evaluate the calibration of your equipment, you must understand the technical details of your equipment that researchers often ignore. In addition to assessing the equipment itself for any problems upon its return, you should also evaluate the calibration certificate and confirm that each of the items required in your order has been fulfilled. The accreditation symbol on the certificate is particularly critical because it ensures that results are traceable, though a statement that specifies traceability is also desirable. Other things that should be included with your equipment and certificate are a coverage factor and a confidence interval that quantify the certainty of the accuracy of the calibration, as well as information on the method used for calibration.


The key to successful calibration is choosing a ISO 17025 and 8655 accredited provider and effectively communicating your needs with that provider. The better the calibrator understands the uses of your equipment and its requirements for your research, the easier it will be to provide exceptional service that ensures that your equipment meets all expected capabilities. You can read Wright’s full article here, or contact TTE with any questions about pipette calibration.