Inertial Torque Device for Viscometer Calibration

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Solution Overview

Problem

Calibration of rotary viscometers is prone to errors due to temperature sensitivity and wear, especially when using standard fluids that require precise temperature control, which can lead to inaccuracies in viscosity measurements.

Innovation Solution

An inertial torque device (ITD) that uses a reaction wheel with a motor and flywheel to produce a controlled torque, eliminating the need for temperature-sensitive standard fluids by simulating the torque experienced during viscosity measurements, thereby ensuring accurate calibration of viscometers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If standard fluids are used for calibration, then the calibration method is simple and useful, but temperature control precision and maintenance requirements cause measurement errors

Engineering Contradiction:
Improvecalibration simplicityVSAvoidcalibration accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent replaces the fluid-based calibration system with a mechanical inertial torque device. Instead of using standard fluids that require temperature control, the invention uses a rotor with known moment of inertia that generates torque through rotational acceleration. This mechanical substitution eliminates temperature sensitivity while maintaining calibration simplicity.

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

Solution Approach 2:

The invention changes the calibration parameter from fluid viscosity (which is temperature-dependent) to moment of inertia (which is temperature-independent). By measuring the rotor's moment of inertia and using it to calculate torque, the system achieves accurate calibration without the need for precise temperature control of calibration materials.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If standard fluids are used for calibration, then calibration can be performed, but wear and temperature sensitivity reduce reliability

Engineering Contradiction:
Improvecalibration operabilityVSAvoidcalibration reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent replaces the fluid-based calibration system with a mechanical inertial torque device. Instead of using standard fluids that require temperature control, the invention uses a rotor with known moment of inertia that generates torque through rotational acceleration. This mechanical substitution eliminates temperature sensitivity while maintaining calibration simplicity.

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

3Measurement precision

If inertial torque device is used for calibration, then temperature control requirements are eliminated and accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvecalibration accuracyVSAvoidcalibration device complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The inertial torque device serves multiple functions: it calibrates the viscometer's torque measurement, verifies the motor's speed control, and provides traceable calibration data. This multi-functionality justifies the added complexity by eliminating the need for separate temperature control systems and multiple calibration standards.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 ITD provides a highly accurate and reliable method for calibrating viscometers by generating a known torque, reducing the uncertainty associated with temperature control and wear, and enhancing the precision of viscosity measurements.

Implementation Method 1

a reaction wheel with a motor and flywheel to produce a controlled torque

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a reaction wheel with a motor and flywheel to produce a controlled torque

Methodology Applied
Scientific EffectMoment of inertia: Moment of Inertia

Data Source

PatentEP3721194B1Intertial torque device for viscometer calibration and rheology measurements
Publication Date: 2023.07.26 AMETEK INC
  • EP3721194B1 patent drawingFigure 1A
  • EP3721194B1 patent drawingFigure 1B
  • EP3721194B1 patent drawingFigure 2A

AI summary

An embodiment includes an inertial torque device (ITD) for calibrating a viscometer. The ITD comprises a body, a coupling for connecting the body to a viscometer measurement interface, a rotatable inertial load device coupled to the body, an electric motor coupled to the rotatable inertial load device and coupled to the body, and a controller configured to calibrate the viscometer by controlling the electric motor to rotate the rotatable inertial load device at a predetermined acceleration to apply a predetermined torque to the coupling connected to the viscometer.