Metrology-Driven Pipette Calibration

Every measurement has a level of uncertainty associated with it. The lower the uncertainty, the better the measurement quality, and the greater the accuracy and reliability of the measurement process. Conversely, high measurement uncertainty signifies a high level of “doubt” about the measurement itself.

To reduce measurement uncertainty, it is necessary to identify the sources of that uncertainty, and also to quantify these factors and report them along with the measurement result. This is the “measurement uncertainty” or mu value. The more tightly these factors are controlled, the smaller the mu and the more accurate the resulting pipette calibration. At TTE Laboratories, we have isolated the following principal factors that impact the accuracy, repeatability and measurement uncertainty of our gravimetric pipette calibrations:

  • TTE Labs is Metrology DrivenAir and Water Temperatures
  • Air Flow
  • Altitude
  • Barometric Pressure
  • Evaporation
  • Purity of our Test Water
  • Relative Humidity
  • Sensitivity of our Measurement Equipment
  • Static Electricity
  • Technical Skill and Performance of our Calibration Staff
  • Vibration

Accordingly, our laboratory and process controls are designed to stabilize these factors, and therefore to provide optimal conditions for a metrology-driven pipette calibration using gravimetric analysis

Accurate Pipette Calibration and Low Measurement Uncertainty Is Impacted By the Facility & Equipment

The ISO 8655 standard defines the sensitivity of the test equipment required for a valid calibration measurement. At TTE Laboratories, we not only meet these requirements, we exceed them, to ensure that even sub-microliter volumes are accurately measured. 

Among the test equipment and systems we use in our pipette calibration to minimize and control measurement uncertainty for every test volume in our scope, are the following:

  • 5-place semi-micro analytical balance (0.01mg), 6-place micro analytical balance (0.001mg) and a 7-place ultra-micro analytical balance (0.0001mg), exceeding the compliance requirements of ISO 8655
  • Annual Proficiency Testing, including both Inter-laboratory and intra-laboratory comparisons to provide an accurate assessment of our pipette measurement performance, both as an independent calibration provider and individually, throughout our trained staff
  • Annual Internal Audit of our quality management systems, including both quality and standard operating procedures
  • Custom temperature and humidity control equipment in continuous operation to assure a stable calibration environment compliant with ISO 8655 required controls
  • Gauge R&R testing to provide individual performance evaluations across our entire calibration scope
  • Laboratory situated underground, directly on a slab floor to provide maximum environmental and anti-vibration stability
  • Marble balance tables maximize stability of our test equipment and afford extra protection against interference with pipette calibration accuracy
  • NIST traceable weight sets – two sets  maintained to ensure continuous compliance to ISO 8655 requirements
  • Validated regular staff training program ensures TTE Laboratories’ staff skill levels are maintained, with opportunities to improve pipette calibration performance

Add all this up and we believe you will agree: TTE Laboratories provides the best pipette calibration service available. Our top 10 clients, who average 10+ years with TTE, agree.