Unique Types of Camera-Based Dimensional Measurement Tools

Dimensional measurement tools are devices that measure 2D elements, like distances and circumferences, as well as 3D and GD&T features. Historically, these have been manual tools that require repeated processes with long measuring times and a lot of calculation. However, new technology has entered the metrology market to help automate and evolve the traditional dimensional measurement tools.

This dimensional measurement equipment is supplied with cameras, software, and technology that technicians can trust to produce the same measurements. Compared to the new tools, handheld tools like micrometers, calipers, and rulers are showing their weaknesses.

In this blog, we’ll dive into unique types of dimensional measuring equipment that are sure to leave manual dimensional instruments in the dust.

Coordinate Measuring Machine

The first type of dimensional measurement equipment is a coordinate measuring machine, also called a CMM. A coordinate measuring machine measures traditional measurements like diameter and distances, as well as 3D/GD&T features like spheres, cone angle, flatness, perpendicularity, and hole position.

There are different types, like bridge, cantilever, gantry, horizontal, or portable. They each use a probe to collect coordinate data points. The probe touches the part and records the measurements. CMMs work well with sturdy parts that won’t be affected by probe contact, so they’re useful on substances like metals and hard plastics. CMM usage is commonly found in the automotive, aerospace, and medical industries.


KEYENCE offers CMMs that are easy for anyone to use, anywhere in the facility including the shop floor. The systems enable accurate 3D, GD&T and CAD comparison with automated reporting capabilities. The two coordinate measuring machines that KEYENCE has are the XM-5000 Series Handheld Probe and the WM-3500 Series Wide Area Coordinate Measuring Machine.

CMM measurement applications include:

  • Machined parts
  • Molds
  • Stamping
  • Die casting
  • Welding distortion

XM Series vs. WM Series

The XM Series and WM Series are handheld CMMs with seven probe markers for the controller camera to capture. Although these tools are handheld, their wireless capabilities give users almost limitless degrees of measurement freedom and a wide range of motion for easy measurement. To get a measurement, simply touch the probe to the part!

Both CMMs use quartz glass and lenses that reduce temperature influence, so they conquer any shop floor. However, the difference between these two CMMs lies in their applications.

The WM reaches a wider area than the XM at 15m, compared to the XM’s 2m. Because of these differences, the WM is ideal for large components that cannot be moved, so the measurement device must go to them, while the XM can support small parts with its stage and up to 6ft parts in general. In this case, one does not necessarily outperform the other; it is solely up to the size measurement needed.

Optical Comparator

Optical comparators are long-used dimensional instruments that utilize a stage, lens, and light to create a shadow on the stage for measurement. These dimensional instruments measure 2D features, like length, width, radius, diameter, and angles. Typical optical comparators measure X and Y axes simultaneously in 2D.

Optical comparators are widely used on smaller parts where it may be hard to use conventional tools to take a measurement and/or fragile parts because there is no contact in the measurement. Industries like aerospace, automotive, semiconductor, medical, and defense use optical comparators for small components.

KEYENCE’s Automated Optical Comparators

KEYENCE’s automated optical comparators, the IM-8000, LM, and LM-X, are automated with vision technology. These dimensional instruments can measure in 2D and collect data in seconds by detecting location orientation and finding millions of data points.

Although KEYENCE offers three different automated optical comparators, these tools are all supplied with baseline features that guarantee easy and accurate measuring regardless of the model.

There are only two steps to measure with any of the optical comparators: place the part(s) on the stage and press the measure button. All models are supplied with technology to auto-adjust and detect edges with a 20-megapixel monochrome CMOS sensor and telecentric lens. Each model has measurement reporting technology that organizes the measurement data. This being said, let’s dive into the differences between the models that make each unique.

IM-8000 Series

In addition to all the standard features the optical comparators have, the IM-8000 is a master of 2D measurements. It also has a rotary unit to capture 360 degree views of a part for quick full part inspection. When the IM-8000 measures, it can collect up to 300 dimensions on 100 parts in as little as one second. Because of the 2D capabilities with the rotary function, the IM-8000 is recommended for technicians who typically use optical comparators, calipers, or micrometers.

LM Series

The LM Series is the high-accuracy version of the IM. The LM Series model measures up to 1,000 parts with +/- 0.1μm repeatability and +/- 0.7μm accuracy, making it ideal for small features on parts with tight tolerances. This model is supplied with features that combat typical measuring difficulties. It has five illumination options to remove the need for light re-adjustment, no-contact height measurement for small areas (20 x 20 μm), and tilt correction for tilted targets.

LM-X Series

The LM-X Series is the newest and most unique measurement system KEYENCE has had in its Instant Measurement Family to date. It is recommended for technicians currently using measuring microscopes or optical CMMs. The LM-X as a multisensor measurement device, as it has upgraded probing and laser capabilities that the other automated optical comparators don’t possess. It is accurate (+/- 0.1 repeatability), has a large measurement area, and can utilize multiple probes to take some 3D measurements when required. Out of KEYENCE’s three optical comparators, the LM-X Series can simultaneously measure the most locations and parts: 5000 locations on 1000 parts at one time.

To make measuring easier with the LM-X, it has an additional front camera to assist the stage camera. The front camera helps you see measured areas by creating a display on the screen for you to follow. As for its measuring area, it has an envelope of 175 x 325 mm.

Use KEYENCE’s Dimensional Measuring Equipment

At KEYENCE, we specialize in vision technology. We offer over 10 dimensional measurement equipment choices within the six types in this list of measuring devices. Our sensors, comparators, profilers, profilometers, micrometers, and CMMs are used in aerospace, construction, automotive, semiconductor, medical devices, and more industries!

Our knowledgeable team is trained to help you pick the best dimensional measuring equipment for your application. Contact us today to start incorporating laser technology into your measuring process!

Related Downloads

XM Series Handheld Probe Coordinate Measuring Machine Catalog

Brochure for the XM-5000 Series Handheld CMM. Portable CMM to easily and accurately measure 3D and GD&T features anywhere including the shop floor and in the machine tool.


IM-8000 Series Image Dimension Measurement System Catalog

Brochure for the IM-8000 Series Image Dimension Measurement System. Accurately measure parts in seconds at the push of a button.