How to Calibrate A Pipette? Simplest Way for Pipette Calibration

Here’s a trick to calibrate your pipette

How Often A Pipette  Calibration Should be Conducted?

The pipette  calibration generally needs to be conducted once a year, and if it is used frequently, calibration needs to be more frequent as well

Here’s A Trick to Calibrate A Pipette

Have you ever wondered whether the pipette you’re using is accurate or not? How do we verify the accuracy of our pipettes? And what should we do if the pipette is not accurate?First, let’s take a look at the errors of different pipettes, as shown in the table below:

The Permissible Error and Measurement Repeatability of The Pipette Capacity

The Simplest Way to Calibrate A Pipette

The simplest way to verify the accuracy of a pipette is to use pure water as a sample, weigh it on a balance, and convert the weight to volume to calculate the volume error. As we all know, the density of water varies at different temperatures, so the temperature of the water and the ambient temperature are factors that affect the results when calibrating a pipette.

How to Calibrate A Pipette?

Another point to note is that different balances must be selected for calibrating different pipettes. The uncertainty of the pipette calibration device (mainly including the balance and thermometer) must meet 1/3 of the maximum allowable error of the pipette. For example, a balance with a calibration interval of 0.1mg cannot be used as a standard device to calibrate a 1μL pipette. After weighing the mass on the balance, the pipette volume at 20°C can be calculated using the following formula:

Pipette Calibration Experiment

verify the accuracy of a pipette

The K(t) at different temperatures is shown in the table below:

Water Tep./℃ K(t)/(cm2/g) Water Tep./℃ K(t)/(cm2/g) Water Tep./℃ K(t)/(cm2/g)
15 1.004213 18.4 1.003261 21.8 1.002436
15.1 1.004183 18.5 1.003235 21.9 1.002414
15.2 1.004153 18.6 1.003209 22.0 1.002391
15.3 1.004123 18.7 1.003184 22.1 1.002369
15.4 1.004094 18.8 1.003158 22.2 1.002347
15.5 1.004064 18.9 1.003132 22.2 1.002347
15.6 1.004035 19.0 1.003107 22.4 1.002303
15.7 1.004006 19.1 1.003082 22.5 1.002281
15.8 1.003977 19.2 1.003056 22.6 1.002259
15.9 1.003948 19.3 1.003031 22.7 1.002238
16 1.003919 19.4 1.003006 22.8 1.002216
16.1 1.003890 19.5 1.002981 22.9 1.002195
16.2 1.003862 19.6 1.002956 23.0 1.002173
16.3 1.003833 19.7 1.002931 23.1 1.002152
16.4 1.003805 19.8 1.002907 23.2 1.002131
16.5 1.003777 19.9 1.002882 23.3 1.002110
16.7 1.003721 20.0 1.002858 23.4 1.002089
16.8 1.003693 20.1 1.002834 23.5 1.002068
16.9 1.003665 20.2 1.002809 23.6 1.002047
17 1.003637 20.3 1.002785 23.7 1.002026
17.1 1.003610 20.4 1.002761 23.8 1.002006
17.2 1.003582 20.5 1.002737 23.9 1.001985
17.2 1.003582 20.6 1.002714 24.0 1.001965
17.3 1.003555 20.7 1.002690 24.1 1.001945
17.4 1.003528 20.8 1.002666 24.2 1.001924
17.5 1.003501 20.9 1.002643 24.3 1.001904
17.6 1.003474 21.0 1.002619 24.4 1.001884
17.7 1.003447 21.1 1.002596 24.5 1.001864
17.8 1.003420 21.2 1.002573 24.6 1.001845
17.9 1.003393 21.3 1.002550 24.7 1.001825
18 1.003367 21.4 1.002527 24.8 1.001805
18.1 1.003340 21.5 1.002481 24.9 1.001786
18.2 1.003314 21.6 1.002459 25.0 1.001766
18.3 1.003288 21.7 1.002459        /        /

Pipette Calibration

Another common method is located at this position

Pipette Calibration step2

With the specialized standard wrench, adjustments can be made. The most convenient option is the electronic pipette, which directly enters the calibration interface, allowing input of calibration results for self-calibration.For non-digital pipettes, the entire calibration process requires patience, with adjustments repeated until the data meets the maximum allowable error requirements.Considerations include:Throughout the calibration process, room temperature should be maintained at (20±5)°C, with temperature fluctuations not exceeding 1°C/h.Distilled water or deionized water should be used, with a temperature difference of ≤2°C between the water and the environment.The pipette should be left in the calibration environment for 4 hours before starting the calibration process

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