Calibration Weight Coupling Mechanism for Gravimetric Instruments
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gravimetric measuring instruments face challenges in maintaining accurate calibration due to geometric deviations and changes in the position of calibration weights, which introduce errors in measurement transducers, especially in high-resolution applications like precision balances and microbalances.
Innovation Solution
A force-transmitting mechanism with a calibration lever and a coupling mechanism divided into two parts that can transmit tractive or compressive forces, allowing the calibration weight to be coupled or uncoupled from the load-receiving portion, minimizing geometric changes and maintaining precise force transmission through a parallel-guided or unidirectional coupling mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the calibration weight is integrally incorporated into the force-transmitting mechanism, then the calibration process is simplified, but geometric deviations and position changes of the calibration weight introduce measurement errors
Solution Approach 1:
The calibration weight is separated from the force-transmitting mechanism into an independent, removable component. This segmentation allows the calibration weight to be detached when not in use, eliminating geometric deviation errors while maintaining calibration simplicity through dedicated calibration mode activation.
Solution Approach 2:
A coupling mechanism acts as an intermediary between the calibration weight and the force-transmitting mechanism. This intermediary enables precise engagement and disengagement of the calibration weight, ensuring accurate force transmission during calibration while preventing position shifts when uncoupled.
2Measurement precision
If a large calibration weight equal to the load capacity is used, then the most accurate calibration value is obtained, but the dimensions and mass of the calibration weight become very large
Solution Approach 1:
A force-magnifying lever arrangement acts as an intermediary between the calibration weight and the measurement transducer. This lever system amplifies the force from a small calibration weight to produce calibration values equivalent to those from a large weight, reducing the calibration weight mass while maintaining calibration accuracy.
Solution Approach 2:
The lever ratio in the force-transmitting mechanism is adjusted to provide mechanical advantage during calibration. By changing the effective force transmission parameter through lever arm ratios, a small calibration weight generates the equivalent calibration effect of a much larger weight.
3Device complexity
If the calibration weight arm is always coupled to the load-receiving portion, then the structure is simplified, but the calibration weight position cannot be changed to minimize geometric deviations
Solution Approach 1:
The coupling between the calibration weight arm and the load-receiving portion is made dynamic rather than static. The coupling mechanism allows the calibration weight arm to be engaged when calibration is needed and disengaged during normal operation, enabling position optimization to minimize geometric deviations while maintaining manageable structural complexity.
Solution Approach 2:
The calibration weight arm serves multiple functions: it acts as a support structure when coupled, provides leverage during calibration, and can be positioned to minimize geometric deviations. This multi-functionality reduces the need for separate dedicated components, managing structural complexity while improving calibration precision.
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 design minimizes errors by absorbing minute position shifts and maintaining unchanged critical geometric dimensions, ensuring accurate calibration and measurement values in gravimetric measuring instruments, even under dynamic conditions.
Implementation Method 1
a coupling mechanism (224) and a calibration lever (220) with a fulcrum (213). The coupling mechanism is divided into a first coupling part (225) and a second coupling part (226) which are oriented relative to each other in such a way that only a tractive or a compressive force can be transmitted between them
Implementation Method 2
The calibration weight (23) is loaded on the first calibration lever arm (221) in such a way that the weight force of the calibration weight (23) acts through the force-transmitting mechanism (110) on the measurement transducer (30) in the same direction as a force resulting from a load placed on the load receiver (40)
Data Source
AI summary
A force-transmitting mechanism of a gravimetric measuring instrument, with a stationary portion, and a load-receiving portion that is joined through a force-transmitting connection to a measurement transducer that is arranged on the stationary portion. A calibration weight may be coupled to the force-transmitting mechanism in such a way as to minimize the degree to which changes of the geometry can affect the force that the calibration weight exerts on the measurement transducer.