Iso 17020 Certification Compliance- Dimensional Checks In Quality Assurance

By Author: Debjyoti Bhismadev Das
Total Articles: 31
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Introduction

Dimensional checks are an important component of quality assurance in many industries. Across industries ranging from manufacturing and construction to aerospace and healthcare, accuracy in measurements is vital for functionality, safety, and compliance.

On this page, we will discuss the significance of dimensional checks in an inspection and how they can be performed.

What Are Dimensional Checks?

Dimensional checks are measurements taken to ensure that a product, component, or structure conforms to specific predefined specifications. These are controls that validate that the dimensions (e.g., length, width, height, and diameter) and angles match the design requirements.

Dimensional accuracy plays the role of ensuring the performance, assembly, and overall quality of the final product.

Why Dimensional Checks are important?

1. Ensuring Product Quality

Then dimensional accuracy is one of the pillars of quality in a product. Even minor variations can jeopardize performance, durability, or safety.
For instance:

Imprecise medical devices can compromise ...
... patient safety.
Incorrectly dimensioned construction materials can create structural integrity issues.

2. Compliance with Standards

Dimensional tolerances are set by several regulatory standards and are often required by practices within many industries. These guidelines ensure that products meet certain safety, environmental, and performance standards. Failure to comply can lead to recalls, fines, or damage to their reputation

3. Enhancing Interchangeability

In industrial domains such as automotive and aerospace, components are typically procured worldwide and must match seamlessly to constructs. Dimensional checks also ensure the inter-changeability of parts across manufacturers, facilitating ease of production and maintenance

4. Reducing Waste and Costs

Early detection of dimensional errors in the production process ensures that defective goods are prevented from progressing to later phases of production, where corrections or replacements can be costlier. This minimizes material wastage, re-work, and costs related to them.

5. Customer Satisfaction

Products that are within acceptable dimensional standards inspire customer confidence and satisfaction. This also assists in creating lasting time relationships and business relationships.

Ways to Make Dimensional Checks:

Methods of making dimensional checks depend on factors such as the complexity, accuracy class, and branch of industry. Below are the most popular approaches:

1. Manual Measurement Tools

Traditional tools are cheap and have simple and basic capabilities.

These include:

Calipers: How did we measure lengths, diameters, and depths with high precision before?
Micrometers: Useful for measuring small dimensions with an accuracy of a few microns.
Height Gauge: Used for vertical measurement from a reference surface.
Measuring Tape: Good for big distances (e.g., construction).
Pros:

It is cheap, and as you likely know, it is very readily available.
It produces easy results for simple measurements.

Cons:

Intuition: Limited precision for complex shapes...
Prone to human error.

2. Coordinate Measuring Machine (CMM)

Coordinate measuring machines (CMMs) are state-of-the-art machines that measure dimensions by probing the surface with a precise point. Calculate dimensions. It is tremendously accurate and flexible.

Applications:

Aerospace components.
Engine parts.
Medical devices.

Pros:

Great accuracy and reproducibility.
Capable of measuring complex geometries.

Cons:

Costly in skill and maintenance, too.
Requires skilled operators.

3. Optical Measurement Systems

These are non-contact systems that use cameras, lasers, or structured light to measure dimensions.

Common types include:

Laser Scanners: the perfect option for big or complicated surfaces.
Vision Systems: 2D or 3D measurement using cameras and image processing.
Photogrammetry: Uses photos to get measurements

Pros:

Contactless, ideal for fragile or elastic media
Quick and effective for large-scale inspections.

Cons:

High initial investment.
May need controlled environments for accuracy.

4. Gauges and Fixtures

However, custom gauges and fixtures are specially designed to check the dimensions or even certain features on the faster side. Examples include:

Go/No-Go Gauges: Basic to see if a dimension is in spec.
Functional Gauges: Confirming Assembly and Fit
Pros:

Quick and easy to use.
Best suited for low-to medium-volume production.

Cons:

Restricted to particular dimensions.
Cannot provide detailed dimensional data.

5. Dial Indicators: Surface Plate

Surface plates are used as a flat reference surface for dimension checks. Dial indicators are measuring tools to measure deviations from the reference.

Applications:

Flat and straightness inspections
Alignment checks.

Pros:

Simple and reliable.
It could be used for various applications.

Cons:

It takes a lot of time for larger or more complex parts.
Restricted by the reference surface accuracy.

6. Reverse Engineering and 3D Scanning

A 3D scanner is a device that observes a real-world object and collects the data necessary to make a digital copy of it. The data is commonly used for reverse engineering or quality control.

Applications:

Prototype development.
Review of detailed elements.

Pros:

Extensive data gathering.
Best for inspecting things of irregular shape.

Cons:

High cost.
It is highly dependent on advanced software for data analytics

Dimensional Checks: What Causes The Big Trouble?

This matters, but dimensional checks are not without issues:

Environmental: Temperature, humidity, and vibration have an impact on measurements.
Equipment Calibration: The same goes for machinery, tools need to get calibrated a regular basis to maintain accuracy.
Operator Skill: Human error and lack of training can compromise results
Intricate Shapes: To measure complex geometries with internal features, specialized tools or strain gauge measurement techniques are required.

Integrating Dimensional Checks Under ISO 17020

Entities looking to achieve ISO 17020 Inspection Bodies need to implement dimensional inspection techniques in their quality management systems.

This involves:

Defined Processes: Creating documented and easily understandable processes for dimensioning checks (i.e., equipment calibration, methods for measurement, etc.)
Training Programs: You should ensure personnel know how to use dimensional metrology and understand the requirements of the standard.
Quality Assurance Systems: QA systems to verify and validate dimensional data to eliminate errors.
Tracing: Keeping a history of all equipment calibration, inspection results, and process verifications to maintain accountability and compliance.

Conclusion

When done correctly, dimensional checks are not just a technical requirement but an integral part of achieving quality and safety for every inspected product. ISO 17020 Accreditation adds value to quality checks by promoting a spirit of excellence, openness, and continual growth among inspection organizations.