Leak-Testing Apparatus for Hand-Held Piston Pipettes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hand-held piston-operated pipettes, especially those with an air cushion, face challenges in leak testing due to the need for precise evaluation of tightness, which is often operator-dependent and not effectively addressed by existing methods, leading to potential false identification of unserviceable pipettes.
Innovation Solution
A method and device for leak testing that involves evacuating the pipette and pipette tip to a gauge pressure below atmospheric pressure, measuring pressure increases over time, and comparing these with reference values to determine the pipette's usability, using a separate leak-testing device that can be automated for precise evaluation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If visual inspection methods are used to detect leaks, then major leaks can be detected, but small leaks are missed and operator expertise is required
Solution Approach 1:
The patent replaces manual visual inspection with an automated pressure measurement system. A pressure sensor electronically detects pressure changes in the pipette chamber, eliminating the need for operator expertise while enabling detection of even small leaks through precise quantitative measurement.
Solution Approach 2:
The system performs self-diagnosis by automatically measuring pressure changes and comparing them against reference values. The automated evaluation process requires no operator intervention beyond loading the pipette, making the leak detection process independent of human skill level.
2Measurement precision
If pressure measurement method is used, then small leaks can be detected, but the system complexity increases
Solution Approach 1:
The pressure sensor and measurement system serve multiple functions: detecting leaks, evaluating pipette tightness, and providing quantitative data for automated decision-making. This multi-functionality justifies the added complexity by delivering comprehensive detection capabilities through a single integrated system.
Solution Approach 2:
The pressure sensor acts as an intermediary between the pipette system and the evaluation process. It translates physical leak conditions into measurable electrical signals, enabling indirect detection of leaks without requiring direct observation or complex mechanical inspection systems.
3Reliability
If manual leak testing is performed, then pipette tightness can be evaluated, but the process is time-consuming and operator-dependent
Solution Approach 1:
The automated pressure measurement system continuously monitors pressure changes throughout the entire pipetting cycle without interruption. This continuous measurement eliminates the need for repeated manual checks, maintaining constant detection activity and significantly reducing total testing time while improving throughput.
Solution Approach 2:
The system automatically compares measured pressure changes against stored reference values and provides immediate feedback on pipette tightness. This closed-loop feedback mechanism enables rapid automated evaluation without requiring operator judgment or repeated manual testing, dramatically increasing productivity while maintaining high reliability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach provides a reliable, quick, and safe method for checking the functionality of pipettes, allowing for timely replacement or repair and reducing failure probabilities by accurately assessing the tightness and potential leaks, independent of operator expertise.
Implementation Method 1
measuring pressure increases over time
Implementation Method 2
evacuating the pipette and pipette tip to a gauge pressure below atmospheric pressure
Data Source
AI summary
The invention relates to a method for leak-testing hand-held piston stroke pipettes and a corresponding leak-testing apparatus. Essential to the system is a holder (8) for the sealed connection of a pipette tip (3) to the leak-testing apparatus. A conduit system (9) with adjacent sections of the leak-testing apparatus forms a specific connecting volume. The pipette tip (3) is evacuated to a measuring pressure below atmospheric pressure. With the vacuum pump (5) disconnected and the connecting volume sealed off, the pressure is measured over a specific time interval, and any possible rise in pressure is determined. An indication of the serviceability of the pipette (2) is generated from the pressure rise determined.