When to Use a Measuring Microscope:

And How to Further Enhance its Capabilities

“Why should someone use a measuring microscope? There are two specific situations that quickly come to mind that call for a measuring microscope. First is the need for

high-accuracy measurements. Second is the need for high-accuracy measurements across large distances beyond the

field of view of a traditional microscope.”

Marc Silverstein Product Manager, Olympus Corporation of the Americas, Scientific Solutions Group

High-Accuracy Measurements First is the need for very quick high-accuracy

measurements. With a measuring microscope, this is accomplished when the operator simply

places their sample on the stage and locates the starting point of the feature they wish to measure. They zero-out the counter and then move across the feature to the end point. The display instantly

shows the distance traveled.

High-Accuracy Measurements Across Large Distances Second is the need for high-accuracy

measurements across large distances beyond the field of view of a traditional microscope. Measuring microscopes are designed to be

accurate to within microns even when measuring features up to 300mm (roughly 12 inches) in the X and Y axis and as high as 175mm

(roughly 7 inches) in height.

Ways to Further Improve Measuring Microscope Performance

Laser Auto Focus: Laser auto focus can be added to a measuring microscope with a motorized Z axis. This combination leads to a system with increased

accuracy and repeatability by eliminating the subjectivity of each operator’s perception

of when the feature is in focus.

Ways to Further Improve Measuring Microscope Performance

Measurement Support Software: Without support software a measuring microscope provides coordinates

of each point measured and leaves all the calculations up to the operator. With something as simple as a circle, getting the diameter can be tricky; you would have to

measure the circle exactly in the middle to measure across. With the right software, any three points on the circle can

be captured and the diameter is instantly calculated. The list of possible measurements is extensive, and the

capabilities of these types of measurements will continue to grow as new software is developed.

Ways to Further Improve Measuring Microscope Performance

Testing Routines: Support software also offers the ability to create testing routines. When an item is being

mass-produced and samples need to be pulled for quality checks, isn’t it helpful when the software guides you

through the test? Software can navigate the operator to each measuring point and then check the results of each

measurement against design value and a tolerance factor. Software can also provide a simple pass/fail with something as uncomplicated as color-coding the results or exporting

your data to your own plant management system.

The Possibilities of Today’s Measuring Microscopes

Today’s newest measuring microscopes offer excellent versatility and high-performance measurement with sub-micron results. Whether samples are small or large, simple or complex— and whether measurements are being taken by a novice or an expert—the features offered by these microscopes can be tailored to fit your needs. If we look at the STM7 measuring microscope from Olympus (Fig. 1), for example, we see that it has been modernized with advanced microscope features. Figure 1: The Olympus STM7 measuring microscope (shown with STM7-BSW measurement support software).

Both Low- and High-Magnification Observation Many conventional measuring microscopes only accept a measuring objective or metallurgical objective, and therefore are unable to meet the requirements for a wide variety of observations. The STM7, however, accepts both a metallurgical objective and a measuring objective by exchanging a revolving nosepiece with a measuring objective adapter. This means that both metallurgical optics and measuring optics are combined in one microscope. The STM7 (Fig. 2) is able to satisfy a range of needs, whether measuring a wide area or a tiny region, measuring the size of differences between features, or assisting the user in deciding their best observation method. Figure 2: STM7 with STM7-BSW software interface.

Both Manual and Motorized Focus Options With focus control available with either manual or motorized operation, the STM7 series allows users to choose the microscope model that best addresses their needs in terms of samples and measurement content, regardless of stage size. Manual Z-axis focus models offer familiar handle operation for rapid vertical movement, convenient for users who need to measure samples with variety of heights (Fig. 3). Motorized Z-axis focus models deliver improved operability and reduce handling fatigue when focusing or taking height measurements (Fig. 4).

Figure 3: Manual Z-axis focus. Figure 4: Motorized Z-axis focus.

Detachable Digital Readout (DRO) To enable swift, convenient checking of measurement results and equipment status, the STM7 offers a detachable digital readout (DRO) that can be positioned either attached the microscope frame (Fig. 5) or placed on a desktop (Fig. 6) in whatever area is most convenient to the user. The DRO indicator displays the device status and settings. Units can be switched between mm, µm, inches, and mil.

Figure 5: Detachable DRO attached to microscope frame.

Figure 6: Detachable DRO positioned on desktop.

Measurement Support Software Measurement support software can enable numerous additional advantages when working with a measuring microscope. STM7-BSW support software allows not only the acquisition and display of a live image, but also observation, measurement, and report creation on the same screen. Threshold-based edge detection and navigation across known samples make finding measurement locations faster, greatly improving work efficiency. STM7-BSW software allows simpler and more accurate measurement of objects with complex shapes, delivered through an easy-to-use interface that clearly displays all output components (Fig. 7).

Figure 7: Sample STM7-BSW interface.

Conclusion Do your operating conditions call for a measuring microscope? If you need fast, highly accurate measurements, chances are that you are best off with a measuring microscope, which can deliver sub-micron precision with extremely simple operation. If you require accurate measurement beyond the field of view

of a traditional microscope, you should also consider a measuring microscope (accurate within microns when measuring features

up to 300mm in the X and Y axis).

Furthermore, today’s newest measuring microscopes can be customized and enhanced with a variety of features

including laser auto focus, a digital readout (DRO), and measurement support software—all worth thinking about

when investing in a measuring microscope.

About the Author Marc Silverstein Product Manager, Olympus Corporation of the Americas, Scientific Solutions Group A member of the Olympus team since 1998, Marc Silverstein manages the operation of measuring microscopes and digital microscopy and is also responsible for downstream product marketing throughout the Americas. From design to launch, Marc plays an integral role in the development and support of today’s newest optical metrology hardware and software.