Gravimetric Moisture Tester Functional Test via Weight Profile Slope
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Solution Overview
Problem
Existing methods for functional testing of gravimetric material moisture determination devices rely on special reference samples, which can be affected by storage-related variations, leading to inaccuracies due to changes in initial mass, and are costly to maintain.
Innovation Solution
A method that determines the weight profile by measuring multiple weight values during heating and extracts a test value from the slope of a representative straight line section of the weight profile, independent of a specific reference weight, allowing for functional testing without requiring well-defined reference samples.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If reference samples are used for functional testing, then the functionality of the measuring device can be tested, but storage-related variations in the reference samples lead to inaccuracies in the test results
Solution Approach 1:
The invention extracts the essential testing information from the weight profile by identifying characteristic points (start point, end point, inflection points) and calculating slopes between these points. This extraction method removes the dependency on absolute reference weights and focuses only on the characteristic changes during heating, thereby eliminating the problem of reference sample mass variation during storage.
Solution Approach 2:
The invention changes the parameter used for testing from absolute weight values to relative weight changes (slopes of weight profile sections). By using the slope of weight change during heating as the test parameter instead of absolute weight differences, the method becomes independent of reference sample mass stability, resolving the contradiction between test reliability and reference sample stability.
2Measurement precision
If special reference samples with stable initial mass are used, then accurate functional testing is possible, but the cost and effort for maintaining sample stability increases considerably
Solution Approach 1:
The invention enables the use of ordinary, inexpensive reference samples that do not require special packaging or controlled storage conditions. By using slope-based analysis of weight profiles, the method works with simple samples that can be easily replaced if needed, eliminating the need for expensive, specially prepared reference samples that require meticulous maintenance.
Solution Approach 2:
The transition from absolute weight measurement to slope-based weight change measurement allows the use of simple, inexpensive reference samples. The test precision is maintained through the characteristic slope values derived from the weight profile during heating, not through the absolute stability of the reference sample mass, thereby reducing maintenance costs and effort.
3Ease of operation
If the reference value is linked to the initial weight of the reference sample, then the functional test can be performed, but variations in initial mass during storage lead to incorrect reference values
Solution Approach 1:
The invention extracts the testing information from the dynamic weight profile during heating rather than from static initial weight values. By identifying characteristic points (inflection points, start and end points of heating sections) and calculating slopes between these points, the method obtains test values that are independent of the absolute initial weight, thereby maintaining procedure simplicity while ensuring reference value accuracy.
Solution Approach 2:
Instead of using the initial weight as the basis for reference values, the invention inverts the approach by using the rate of weight change (slope) during heating as the fundamental test parameter. This inversion makes the test procedure equally simple while eliminating the accuracy problem associated with initial weight variations during storage.
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 enables accurate functional testing of the measuring device independently of storage-related variations, eliminating the need for special reference samples and reducing costs associated with maintaining their stability.
Implementation Method 1
heating the material to be measured according to a predetermined, monotonous heating curve
Implementation Method 2
determining a weight curve of the material to be measured by measuring at least two weight values at different times
Data Source
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AI summary
The invention relates to a method for functionally testing a measuring device for gravimetrically determining material moisture (10), comprising a weighing apparatus and a heating device (60) for heating a measurement medium (50) positioned on a load receiving means (40), comprising the steps of: - positioning the measurement medium (50) on the load receiving means (40), - heating the measurement medium (50) according to a predefined monotonous heating profile, - determining a weight profile of the measurement medium (50) by measuring at least two weight values at different times, at least one of which is measured during the heating step, - extracting a test value from the determined weight profile, - comparing the test value with a stored reference value. The invention is distinguished by the fact that the weight profile is determined by measuring a plurality of weight values at different times during the heating step and the magnitude of the gradient of a straight line segment representative of a characteristic test area (160) of the weight profile is determined as the test value and by the fact that the reference value is a gradient value which is expected and stored for the measurement medium.