Air Density Weighing Using Dual Weight Pieces for Buoyancy Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high-precision weighing and calibration methods for weight pieces require expensive and complex equipment for determining air density and buoyancy correction, leading to high maintenance costs and inaccuracies due to environmental conditions, making them unsuitable for private laboratories.
Innovation Solution
A non-vacuum weighing system using an electronic balance with two weight pieces of different materials and volumes, along with a controller to determine air density and buoyancy correction, utilizing equations based on known characteristics of these pieces, eliminating the need for separate measurements of pressure, temperature, and humidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the 3-quantity-method is used to determine air density with separate electronic measuring instruments (barometer, thermometer, hygrometer), then air density can be determined, but the equipment cost and maintenance effort increase significantly
Solution Approach 1:
The patent combines multiple separate electronic measuring instruments (barometer, thermometer, hygrometer) into a single integrated air density measurement system. The controller receives signals from all three sensors and calculates air density centrally, reducing equipment complexity and maintenance effort while maintaining measurement precision.
Solution Approach 2:
The controller serves multiple functions: it processes signals from the barometer, thermometer, and hygrometer, calculates air density using the CIPM-81/91 formula, and provides the result for buoyancy correction. This multi-functional approach eliminates the need for separate processing systems for each parameter.
2Measurement precision
If separate electronic measuring instruments are used for pressure, temperature, and humidity measurements, then air density can be calculated, but periodic re-calibration is required increasing maintenance effort and laboratory down-time
Solution Approach 1:
By integrating three separate calibration requirements into a single unified measurement system, the patent reduces the frequency and complexity of calibration activities. The controller performs centralized calculations, and calibration can be done more efficiently by considering the interdependence of the three parameters.
Solution Approach 2:
The system continuously monitors all three parameters (pressure, temperature, humidity) and their interrelationships, allowing for self-validation and reduced need for external calibration. The controller uses feedback from all sensors to maintain accurate air density calculations with minimal intervention.
3Measurement precision
If four separate measuring instruments are used (barometer, hygrometer, thermometer, balance), then measurements can be taken, but inaccuracy increases due to different environmental conditions at different locations
Solution Approach 1:
The patent positions all four measuring instruments (barometer, hygrometer, thermometer, and balance) in close proximity within the same environmental zone. This ensures that all measurements are taken under identical environmental conditions, eliminating location-based variability and improving measurement consistency and reliability.
4Measurement precision
If advanced electronic measuring instruments are used to achieve very low uncertainties in air density components, then measurement precision improves, but equipment cost increases
Solution Approach 1:
The patent achieves low measurement uncertainty not through individually advanced instruments, but by optimizing the combination and integration of standard instruments. The controller uses the CIPM-81/91 formula which accounts for the interdependence of pressure, temperature, and humidity parameters, allowing accurate air density determination with conventional equipment.
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
Provides accurate air density determination and buoyancy correction efficiently, reducing resource intensity and equipment costs, suitable for private laboratories, and maintaining precision without complex procedures.
Implementation Method 1
the resulting force, F, on any physical body immersed in a gravitational field and in an atmosphere (or liquid), is the directional sum of the gravitational force, G
Implementation Method 2
the buoyant force, F buoy , according to Archimedes' law, is the product of the volume, V, of the body and the gravitational acceleration, g, and the density, ρ, of the surrounding liquid
Data Source
Figure 1~3
Figure 4
Figure 5
AI summary
The invention relates to the field of weighing, in particular of weighing in mass calibration and/or weighing laboratories. The invention provides a method for determining air density ρa as well as a related weighing system 1 and a related set comprising a mass artefact 11. A method for determining an air buoyancy correction to a measured weighing value, the method using the determined air density, as well as a related computer program and a related computer-readable signal or medium are provided as well.The method comprises a step S2 of providing a mass artefact as a first weight piece 11 and at least two of a first mass value m1 representing the mass of the first weight piece, a first density value ρ1 representing the density of the first weight piece, and a first volume value V1 representing the volume of the first weight piece. The method comprises further a step S3 of providing a second weight piece 12 as well as a second density value ρ2 representing the density of the second weight piece. The method comprises further a step S4 of determining a first weighing value (w1, Δw) of the first weight piece 11 using the weighing system 1, wherein the first weighing value is determined in the air for which the air density is to be determined.