Loss-in-Weight Scale Calibration for Precise Discharge Flow Control

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Solution Overview

Problem

Existing calibration methods for loss-in-weight scales require extended periods for data stabilization, leading to increased time and material wastage, and result in low precision due to the limited number of calibration data sets used.

Innovation Solution

A method that continuously changes control outputs to avoid data stabilization time, by setting sampling points and calculating functional relationships between control outputs, time, and discharge flow rates, allowing precise control of discharge flow rates by directly inputting control output values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If control outputs are switched at discrete intervals for calibration, then calibration data can be collected, but data stabilization time is required and calibration time increases

Engineering Contradiction:
Improveflow rate measurement precisionVSAvoidcalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies continuous action by continuously changing the control output value throughout the calibration process rather than switching between discrete levels. The control output is increased continuously from initial value to maximum value while collecting flow rate data at multiple sampling points along the continuous curve, eliminating the need to wait for data stabilization at each discrete level and significantly reducing total calibration time.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent implements dynamics by transitioning from static discrete control output levels to a dynamic continuously varying control output. The control output changes continuously over time, creating a dynamic calibration process that captures the relationship between control output and flow rate across the entire operating range in a single continuous operation rather than through multiple static measurements.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If control outputs are switched at discrete intervals for calibration, then calibration data can be collected, but material consumption increases due to extended calibration time

Engineering Contradiction:
Improveflow rate measurement precisionVSAvoidmaterial consumption
Core Design Contradiction:
Measurement precisionVSLoss of substance

Solution Approach 1:

The continuous change of control output eliminates idle stabilization periods where material would be consumed without useful data collection. By continuously varying the control output and collecting data along the continuous curve, the calibration process minimizes unnecessary material consumption while maintaining measurement precision.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent rushes through the calibration process by eliminating the stabilization waiting period at each discrete control level. Instead of pausing to wait for data stabilization, the method continuously moves through the control output range, skipping the unproductive stabilization phase and directly collecting useful calibration data throughout the process.

Inventive Principle:
Principle #21Skipping (Rushing through)

3Ease of manufacture

If only several sets of calibration data are used, then calibration process is simple, but calibration curve precision is low

Engineering Contradiction:
Improvecalibration process simplicityVSAvoidcalibration curve precision
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent segments the continuous calibration curve into multiple discrete sampling points. By collecting flow rate data at numerous sampling points (e.g., 100 or more points) along the continuous control output range, the method creates a highly detailed calibration curve that accurately represents the relationship between control output and flow rate, significantly improving precision while maintaining computational simplicity through standard curve fitting techniques.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent adds the dimension of continuous variation to the calibration process. Instead of using a small number of discrete control levels, the method varies the control output continuously across the entire operating range, effectively adding a temporal dimension to the calibration data collection and generating a much more precise calibration curve through continuous sampling.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 method enables precise and efficient control of discharge flow rates in loss-in-weight scales, reducing material wastage and calibration time, while improving the accuracy of flow rate control.

Implementation Method 1

a weighing sensor 104 is used to measure the weight of a weighing hopper 105

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP4127616B1Method for controlling discharge flow rate in a loss-in-weight scale
Publication Date: 2025.04.30 METTLER TOLEDO (CHANGZHOU) MEASUREMENT TECH CO LTD
  • EP4127616B1 patent drawingFigure 1
  • EP4127616B1 patent drawingFigure 2

AI summary

A method for controlling a discharge flow rate of a loss-in-weight scale is provided, wherein control outputs are continuously changed to save the time necessary for data stabilization, and a curve of relationship between the discharge flow rate and the control output is obtained by using the functional relationship between the control output and time and the functional relationship between the material weight and time. The discharge flow rate can be precisely controlled by directly selecting or inputting a value of the control output, to achieve the objectives of direct controlling and of avoiding the time for data stabilization.