An Introduction to Optical Measuring Systems

Introduction to Optical Measuring Systems

The speaker introduces the webinar and discusses the diverse audience present, highlighting the aim to provide valuable information on optical measuring systems for both experienced engineers and newcomers.

McCrone Group Divisions

• Alan Vitous introduces The McCrone Group, consisting of three divisions:

• Materials Analysis Division (McCrone Associates): Offers analysis using various techniques.

• Hooke College of Applied Sciences: Provides education and training in microscopy.

• McCrone Microscopes & Accessories: Instrument sales division offering a range of laboratory tools.

Optical Measuring Systems Overview

• Distinction between inspection and measurement applications:

• Inspection applications are qualitative and subjective, focusing on surface details and defects.

• Measurement applications are quantitative, involving precise measurements like feature dimensions.

Types of Microscopes for Inspection

The speaker explains different types of microscopes used for inspection purposes in optical measuring systems.

Inspection Microscope Types

• Various types of inspection microscopes include:

• Inverted materials microscopes with objectives under the stage.

• Upright materials microscopes with objectives at the top.

• Stereomicroscopes providing stereoscopic viewing for a 3-D inspection aspect.

Measuring Instruments

• Focus on profile projectors and toolmakers/measuring microscopes:

• Profile projectors/comparators offer up to 500X magnification with measuring capabilities.

Profile Projectors Configuration

Detailed explanation about profile projectors or comparators used in optical measuring systems.

Profile Projector Features

• Configuration variations of profile projectors:

• Vertical comparators have objectives looking down onto specimens vertically.

Overview of Measuring Microscopes and Comparators

In this section, the speaker discusses the use of measuring microscopes and comparators in industrial settings, highlighting their functionalities, differences, and considerations for choosing between them.

Horizontal Comparators vs. Measuring Microscopes

• American manufacturers prefer horizontal comparators due to their efficiency in handling large and heavy parts.

• Measuring microscopes operate similarly to comparators but offer options like mounting cameras or using eyepieces for magnification.

• Factors influencing the choice between a measuring microscope and a comparator include part size, area of interest, complexity of measurements, need for z-axis measurements, ergonomic preferences (eyepieces vs. screens), documentation requirements, and throughput considerations.

Measurement Methods on Comparators and Microscopes

• Deciding factors for instrument selection include the type of measurements needed (simple vs. complex), z-axis involvement, ergonomic preferences (eyepieces vs. screens), documentation needs, and throughput requirements.

• Field of view measurements or stage measurements are two ways to conduct measurements on comparators or toolmakers' microscopes.

Utilizing Overlays and Specialty Charts

• Comparators utilize overlay charts for field of view measurements while microscopes employ eyepiece reticles for similar purposes.

• Stage measuring systems allow measurement of larger parts beyond the field of view and facilitate feature construction as well as z-axis height measurements.

Customized Tools for Enhanced Precision

• Specialized charts like thread pitch dimensions or custom overlays aid in precise measurement tasks on comparators.

• Custom-made overlays from CAD drawings calibrated to screen size enhance inspection speed and accuracy.

Eyepiece Reticles and Specialty Eyepieces

• Protractor screens on comparators enable angle readings with switchable display modes while eyepiece reticles in microscopes support field of view measurements.

Angle Measurement and Field of View

In this section, the speaker discusses angle measurement techniques and how field of view varies based on magnification levels and screen sizes in comparators and microscopes.

Angle Measurement Techniques

• Manual reading eyepieces allow for precise angle measurements.

• Software packages like Nikon Elements enable point-to-point measurements and circle measurements using cameras mounted on microscopes.

Field of View in Comparators and Microscopes

• Field of view is influenced by screen size; a 10X magnification on a 12-inch comparator provides a 30mm field of view.

• Higher magnifications result in smaller fields of view; comparators offer lower magnification but wider fields compared to microscopes with higher magnification.

Stage Measuring Systems and Digital Readouts

This part covers stage measuring systems in comparators and microscopes, along with digital readout systems like the Nikon SC series and Quadra-Check system.

Stage Measuring Systems

• X-Y stages with linear or rotary encoders facilitate distance measurement on both comparators and microscopes.

• Features can be constructed or related for measurement purposes using x-y tables.

Digital Readout Systems

• The Nikon SC series offers X-Y or X-Y-Z digital readouts, while the Quadra-Check system by Metronics provides advanced capabilities for measuring features.

• Encoders on stages are crucial for z-axis measurements in measuring microscopes.

Part Positioning and Feature Measurement

This segment delves into establishing part position, setting datums, probing features, utilizing Measure Magic®, and different types of feature measurements.

Part Positioning

• Skewing parts helps establish zero points or datums for accurate feature measurement.

• Probing points aids in setting x-y axes alignment between parts and stages during positioning.

Feature Measurement Techniques

• Measure Magic® assists in determining shapes like circles, angles, or lines based on probed points' distribution.

Detailed Overview of Measurement and Analysis Techniques

In this section, the speaker discusses various measurement and analysis techniques using annotation tools to probe points for determining angles, constructing features like circles, distances between objects, and intersection points.

Annotation Tools for Probing Points

• Annotation tools allow probing more points than required.

• Probing points helps determine angles by selecting specific points on lines or shapes.

• Options include choosing the number of points to determine a circle using algorithms like least-squares best fit or ISO schema.

Constructing Features and Distances

• Measuring distances between circles involves options like center point to center point or nearest/farthest edges.

• Creating features such as bolt hole circles by combining previously probed circles.

Overview of Profile Projectors and Measuring Microscopes

This part covers different profile projectors and measuring microscopes available in the market with varying specifications and configurations.

Profile Projectors

• The V12 is a benchtop instrument with a 12-inch screen, offering digital readout options and digital protractor screens for angle measurements.

• The H-14-LED horizontal comparator has a 14-inch screen capable of holding heavy parts up to 125 pounds.

Measuring Microscopes

• The V20 is a floor-standing 20-inch profile projector with multiple objective options.

• The MM series includes models like MM-200 with different configurations such as monocular eyepiece tube or camera-only versions.

Advanced Measuring Instruments

This segment delves into advanced measuring instruments like MM-400 and MM-800, highlighting their features, configurations, stage sizes, height capacities, objective mountings, and focus aids.

Advanced Measuring Instruments Comparison

• Both MM systems offer similar features but differ in stage sizes; MM-800 provides larger stage dimensions compared to MM-400.

Sophisticated Measuring Systems

Discusses sophisticated measuring systems beyond basic instruments including computer-based systems for measurements through software integration and advanced CNC programmable systems like Nexiv for multi-sensor capabilities.

Sophisticated Measurement Systems

• Mention of computer-based systems integrating comparators into software for measurements.