Measure and inspect precise features by projecting a magnified shadow or image of your part onto a screen. These optical comparators work similarly to overhead projectors, but with fixed magnification to preserve proportions. Because of how easy they are to set up and use, they’re a staple in most machine shops. From o-rings to castings, they work to inspect parts with simple or complex geometries. They shine light from the side, so unlike vertical comparators, your part can be held from underneath for stability. Unlike traditional optical comparators, these comparators are compact to fit easily on a benchtop.

To use these comparators, choose profile or surface lighting. Profile lighting creates a shadow of your part, which you can use to plot points for precise measurements. To plot each point, move the stage the parts rests on until the point lines up with the crosshair on the projector screen. For precision, the stage moves in increments thinner than a sheet of paper. Surface lighting makes these comparators work like an illuminated magnifier, blanketing the part with even light to reveal scratches, dents, and other surface flaws.

These comparators come with a variety of features to streamline your inspection process. For a quick way to compare manufactured parts to designs, set desired dimension and tolerance limits. You can also create a program that guides anyone using the comparator on what steps to follow, so each part is inspected the same way. To save everything for later, print the data or export it as a spreadsheet or text file to a computer with a USB or RS-232 connection.

Changing the magnification is as easy as twisting the current lens until it pops out and twisting in a new lens (sold separately).

Optical comparators with edge detection increase accuracy and efficiency by reducing human error. No need to identify each edge yourself with the crosshair—these comparators register whether they are passing over your object's shadow or a gap, such as a hole or cutout.

Rotary vises (sold separately) give you a secure way to hold up and rotate objects.

Cabinets (sold separately) can serve as a stand for your comparator and as storage for lenses and other accessories.