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Abstract. In order to solve the problems of the failure of disposable tip insertion which happens in the pipetting process of most multi-station and high-throughput pipetting devices, this paper proposes a high-rigidity screw-type pipette shaft–disposable tip assembly mechanism with excellent auto-centering effects based on the principle of the ball screw drive. The stiffness model of the new pipetting device is established, and its stiffness and axial deformation are analyzed. This new mechanism was introduced to a multi-station and high-throughput pipetting workstation, and the process of pipetting disposable tips is simulated by ANSYS software. The analytical results show that the stiffness value of the new pipetting device is approximately 90 N/µm, and the amount of deformation of the z-axis manipulator is reduced by about 60 % compared to the original pipetting device. Finally, physical verification of the prototype was carried out in the work. The test results show that the new pipetting workstation can increase the tightening rate of the tips by approximately 12 % after optimization when 96 tips are inserted in a single press. In addition, the pass rate of the tightness test of the optimized pipetting workstation has increased by approximately 20 %.

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Automatic meteorological station is important for meteorological observation and the existence of outliers in the observational data is inevitable. The paper proposes outlier detection for observational data of automatic meteorological station based on least square support vector machine (LS-SVM). The method establishes the LS-SVM model for the meteorological factor and uses the model to evaluate the observational data. If the observational data deviate from the model, they would be seemed as outliers. The ground temperature data observed by two real automatic meteorological stations are used in experiments. Experiments results verify that the proposed method realize outlier detection for observational data of automatic meteorological station effectively and ensures subsequent process and analysis of the meteorological data.

The accuracy of nucleic acid extraction and diagnosis depends on the sealing performance of the pipetting device. The rubber seal ring at the front end of the pipette shaft is a critical component for ensuring the sealing performance of the pipetting device. In this study, an accurate prediction and analysis were made on the fatigue life of the pipette shaft seal ring. ABAQUS was used to simulate the assembly process of pipette shaft seal ring and disposable tip, and the dangerous cross-section segments on the seal rings were preliminarily identified according to a stress nephogram. Based on the continuum damage mechanics theory, the fatigue life prediction model was built where the effective strain was taken as a damage parameter, and the fatigue life of the dangerous cross-section of the pipette shaft seal ring was calculated. By observing failed seal rings in actual use, it was found that the worn positions of the failed seal rings were the same as the sites of the shortest-lived node segments, thus verifying the accuracy of fatigue life prediction model and fatigue life analysis.