Visual inspection systems: What to choose and when

Visual inspection is a non-destructive testing method involving visual examination of samples of varying kinds. For some products, it’s enough to visually inspect an item by looking it over with a simple visual inspection system. For others, it involves specialized equipment which enhances the testing process.

In this blogpost, we’ll discuss three visual inspection systems typically used for visual inspection processes in industries such as agriculture, electronics, plastic and metal manufacturing.

OPTION 1: DESK MAGNIFIER

Choosing a desk magnifier as your visual inspection system

For many, a desk magnifier, also known as a tabletop magnifier or loupe lamp, is the first visual inspection system they encounter.

The desk magnifier is characterized by its long adjustable arm and the integrated magnifying glass. A desk magnifier will often have an integrated light that can be adjusted not only in intensity but also temperature to suit the inspected sample or workstation location.

Benefits of a desk magnifier

A clear benefit of the desk magnifier is its flexibility. It can be installed almost anywhere and can be moved around easily. Even after being installed, it’s easy to push out of the way when it’s not needed.

Being an affordable and widely available solution, the desk magnifier is often used on larger sites with high quantity needs. The desk magnifier is also ideal for low magnification tasks and required little to no training.

When you should consider replacing your desk magnifier

On the other hand, the low magnification capability is also limiting for the type of tasks a desk magnifier can assist in. Further, the desk magnifier has no documentation capabilities, a process that has become more and more important for many businesses.

For low magnification tasks, however, or if you have a limited budget or need high volumes, a desk magnifier might be a suitable visual inspection system for your needs.

OPTION 2: STEREO MICROSCOPE

Choosing a stereo microscope as your visual inspection system

Being easily identifiable with its ocular, zoom and focus knobs, lens and base, a stereo microscope is often what people think of when picturing a microscope.

With the first true stereo microscope being developed in the 19^th century, it has become a standard piece of equipment in many laboratories.*

When to use a stereo microscope

In quality control and visual inspection processes, the stereo microscope often replaces desk magnifiers when they can no longer do the job adequately. In comparison, the stereo microscope has higher magnification capabilities, ranging from single digit magnification levels to more than 500x magnification.

With its zoom and focus knobs, it’s also easier for the operator to fine adjust the microscope accordingly to the sample at hand. This makes the stereo microscope much more versatile than a desk magnifier.

When you should consider replacing your stereo microscope

Stereo microscopes often come with a high price point, making it an expensive investment that many are hesitant to make in the first place and won’t replace until it’s absolutely necessary after eventually purchasing it.

This is understandable given the often superb image quality of the microscope. However, similar to desk magnifier, the stereo microscope has no documentation capabilities, making it difficult for operators to document their work and findings. Many companies therefore start looking for alternative equipment when documenting their work becomes an integral part of their visual inspection processes.

With increasingly complex products in their product portfolio, often requiring second opinions from colleagues before an operator can pass or fail a sample – or simply due to extensive training needed for new operators, many companies also find that it is difficult for operators to collaborate and inspect samples together due to only one operator being able to use the ocular at a time.

Many microscope operators also experience work related pain as a result of the awkward posture and repetitive moments related to using a stereo microscope. Having to bend their necks to look through the ocular often results in neck pain and operator fatigue, affecting the efficiency of the visual inspection team.

To stay competitive and increase efficiency, many companies want to eliminate the subjective aspect of visual inspection. Instead of relying on the accuracy of the individual operator, companies want the microscope to perform the analysis for them with the aim that they’ll work more accurately, consistently and faster. This, however, is not an option on a stereo microscope, leading companies to look for a digital alternative.

OPTION 3: DIGITAL MICROSCOPE

Choosing a digital microscope as your visual inspection system

When looking for a digital alternative to a stereo microscope, many comes across the USB microscopes that can be bought online at a very low price point. What many experience, however, with these microscopes is poor image quality and limited added features – something users were otherwise hoping to find in the digital microscope.

This sometimes prevents people from further exploring the capabilities of a digital microscope and retort back to their desk magnifier or stereo microscope when the USB microscope doesn’t live up to their expectations.

Finding a good quality digital microscope, however, can provide users with many advantages that simply aren’t possible with other non-digital inspection systems – and often at a fraction of the price of stereo microscope.

Benefits of a digital microscope

Perhaps the biggest differentiator from a desk magnifier and stereo microscope is the built-in computer of the digital microscope that allows companies to utilize software and features as part of their inspection process to eliminate the subjective analysis of each sample.

With a digital microscope, the operator can also look straight ahead to inspect their sample on a monitor instead of bending their neck to look through an ocular. The digital display not only relieves operators of neck and back pain, reducing operator fatigue. It also makes it easier for operators to collaborate by being able to inspect a sample together.

The digital display also allows operators to easily document their work. The microscope is often referred to as a computer microscope due to its ability to capture and store images of the performed visual inspection.

When to look for alternatives to a digital microscope

At the core of a digital microscope is the built-in computer that allows for software updates. With software updates, the microscope can be updated with new features and apps based on technology that simply weren’t available when the microscope was first purchased. This flexibility means that many find it unnecessary to replace a digital microscope if it is unsuitable for certain processes currently, seeing how there’s always the possibility that it’ll be able to in the future.

However, if it becomes necessary with magnification levels simply outside the capabilities of the microscope or if there’s not enough work depth underneath the microscope due to the construction of the microscope, it might be time to look for alternatives.

In summary

There’s a wide variety of visual inspection systems available for businesses to choose from. For non-destructive testing, many either use a desk magnifier, stereo microscope or digital microscope. Some even choose a hybrid of the stereo and digital microscope to obtain the digital display without the advanced features and apps.

Which visual inspection system is the right system for each business will not only depend on the company’s specific inspection processes but also the required quantities and allocated budget.

Sources:

https://www.news-medical.net/life-sciences/What-are-Stereo-Microscopes-Used-For.aspx