Digital Hydrometer With Inductive Sensor For Acid Concentrate

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Solution Overview

Problem

Traditional hydrometers are difficult to read accurately due to small and closely spaced numbers and scales, which is critical for measuring the specific gravity of acid concentrates in hemodialysis clinics, requiring a more precise and accurate method for determining the acceptability of acid concentrate batches.

Innovation Solution

A digital hydrometer system that includes a digital hydrometer base with an inductive distance sensor and a hydrometer float with a metallic object, allowing for precise impedance measurements and digital display of specific gravity, enabling calibration and determination of the acceptability of acid concentrate batches based on specific gravity values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a traditional analog hydrometer is used, then the device structure is simple, but the measurement precision and readability are poor due to small and closely spaced numbers and scales

Engineering Contradiction:
Improvespecific gravity measurement precisionVSAvoiddevice structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical reading system of traditional hydrometers (visual reading of small scales on a float) with an electronic sensing system. An inductive distance sensor detects the position of a metallic object on the hydrometer float, converts it to an electrical signal, and processes it to determine specific gravity. This substitution eliminates the readability problem while maintaining the basic hydrometer floating mechanism.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a metallic object attached to the hydrometer float as an intermediary element. This metallic object serves as a marker that can be easily detected by the inductive distance sensor, enabling precise measurement of the float's position without requiring direct visual reading of small scales on the float itself.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If traditional visual reading method is used, then the device operation is simple, but the measurement accuracy is insufficient for critical applications like acid concentrate verification

Engineering Contradiction:
Improvespecific gravity reading accuracyVSAvoidoperation complexity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system performs automatic measurement and calculation without requiring manual reading interpretation. The inductive distance sensor automatically detects the metallic object position, the processor circuit calculates specific gravity based on the detected position, and the results are displayed digitally. This eliminates human error in reading small scales while the overall operation remains simple - just place the hydrometer in the liquid and read the digital display.

Inventive Principle:
Principle #25Self-service

3Reliability

If analog hydrometer scales are used, then the manufacturing cost is low, but the reliability of measurement is insufficient for critical quality control

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical scale system with an electronic sensing and processing system. The inductive distance sensor provides reliable, repeatable measurements of the float position, and the processor circuit reliably calculates specific gravity using programmed algorithms. This electronic system provides superior reliability compared to manual scale reading, especially for critical quality control applications.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

The digital hydrometer system provides accurate and precise specific gravity measurements, enhancing the reliability of determining the acceptability of acid concentrate batches and improving the measurement process in hemodialysis clinics.

Implementation Method 1

an inductive distance sensor and a hydrometer float with a metallic object, allowing for precise impedance measurements

Methodology Applied
Scientific EffectInductive sensing: Electromagnetic Induction

Data Source

PatentEP3523625B1Digital hydrometer assistant reader
Publication Date: 2023.08.30 FRESENIUS MEDICAL CARE HOLDINGS INC
  • EP3523625B1 patent drawingFigure 1
  • EP3523625B1 patent drawingFigure 2
  • EP3523625B1 patent drawingFigure 3A~4B

AI summary

A digital hydrometer and methods of digitally displaying a specific gravity measured by a hydrometer are provided. The digital hydrometer can comprise a base, a displacement vessel, an inductive distance sensor, an output circuit, and a hydrometer float. The displacement vessel and inductive distance sensor can be mounted in or on the base. The displacement vessel can hold a displacement fluid. The hydrometer float can float in the displacement fluid. The output circuit can be in electrical communication with the inductive distance sensor and comprise a digital display device configured to display a digital value that is commensurate with a change in impedance attributable to the proximity of a metallic object, in the hydrometer float, to the sensor or its inductor. The digital value can be a specific gravity of the displacement fluid.