Used Optical Comparators, Video Measuring Machines, and Hardness Testers at Auction

A used optical comparator, video measuring machine, or hardness tester rarely draws the crowd that a CNC mill or lathe does on auction day, but for machine shops, calibration labs, and in-house QC departments these are the tools that keep an entire operation compliant with print tolerances and customer audits. Whether you are bidding on a bench-model optical comparator to build out a quality department on a budget, or preparing to liquidate a video measuring machine and hardness tester as part of a shop closure, understanding what actually drives value in metrology equipment for sale will save you money as a buyer and put more money in your pocket as a seller.

What Actually Drives Value in Used Metrology Equipment

Optical Comparators

Optical comparators, also called profile projectors, remain a staple in shops that check formed parts, stampings, and turned or ground components against an overlay chart or a digital edge-detection system. Value comes down to a short list of factors: screen size (bench units typically run around 14 to 16 inches, floor-standing units roughly 20 to 30 inches), the condition and coating of the lens set (common magnifications include 10x, 20x, 31.25x, 50x, and 100x), whether the unit carries a digital readout such as a Newall, Acu-Rite, or Mitutoyo QM-Data package, and overall optics clarity. Brands that tend to hold demand on the used market include Deltronic, Scherr-Tumico, Jones & Lamson, Suburban Tool, Starrett, and Mitutoyo. An older, purely manual comparator with a clean screen and sharp optics can still be a workhorse for a shop that only needs occasional profile checks, while a comparator paired with a full digital readout and geometric measurement software typically commands a premium.

Video Measuring Machines

Video measuring machines (VMMs) have absorbed a lot of the work optical comparators used to do, using a camera and programmable lighting instead of a projected shadow to capture edges, and many add touch-probe or laser sensors for true multi-sensor measurement. Unlike a tactile CMM that physically touches every feature, a VMM measures primarily from the image, which makes it fast on thin, soft, or delicate parts. OGP's SmartScope line, Mitutoyo's Quick Vision series, and Starrett's vision systems are among the names that surface most often on the used market. Value here is driven by the stage travel and repeatability, camera and lens condition, ring-light and surface-illumination function, and, above all, the software license. Many VMMs run proprietary software tied to a specific PC and Windows version, so a buyer needs to confirm that the software dongle, license, and calibration files transfer with the machine, not just the hardware. A CNC VMM with working software and a recent calibration is worth substantially more than the same model with a locked or missing license.

Hardness Testers

Rockwell, Brinell, and Vickers or microhardness testers are the third pillar of a used metrology lot, common from names such as Wilson, Instron, Leco, Struers, and Buehler. A basic bench-top Rockwell tester with manual load application and dial indication still sells reliably to smaller shops, while motorized or digital units with automatic load cycling, digital readout, and data output to SPC software bring more at auction. What matters most is the condition of the indenter and anvil, whether the load system carries a current calibration certificate, and whether the unit still holds accurate readings against certified test blocks. A tester with documented calibration traceability is a far easier sell than one with an unknown service history.

What Buyers Should Inspect Before Bidding

A metrology lot rewards a careful pre-bid inspection more than almost any other equipment category, because a small optical or mechanical fault can quietly ruin measurement accuracy long after the sale. Focus on these points:

• Screen and optics: check the projection screen or camera monitor for scratches, haze, or dead pixels, and verify crosshair or edge-detection sharpness at multiple magnifications.
• Axis travel: jog the X and Y (and Z, if equipped) stages by hand or through the controller and feel for binding, backlash, or worn ways.
• Digital readout function: confirm the DRO powers on, holds zero, and reads consistently against a known reference.
• Software and licensing: for video measuring machines, ask whether the measurement software, dongle, and any calibration or artifact files are included and transferable.
• Lighting: verify backlight, surface light, or ring-light illumination is even and functional, since inconsistent lighting throws off edge detection.
• Calibration history: request the most recent calibration certificate. Equipment with NIST-traceable calibration on file is worth more and easier to put back into service.
• Indenter and anvil condition on hardness testers: look for pitting, chipping, or wear that would affect repeatability.

How Bidding on Metrology Equipment Works at KD Auctions

KD Auctions runs every sale fully online, so you are bidding against other buyers in real time rather than at a live ring, and detailed photos, specs, and condition notes are posted with each lot ahead of time. Optical comparators, video measuring machines, and hardness testers most often come up as part of larger machine shop or manufacturing plant liquidations, sometimes as an individual lot and sometimes grouped with other QC or gage-room equipment. As with all used equipment, metrology items sell as-is, where-is, so plan on budgeting for a recalibration after you win a lot, especially on anything without a recent certificate. Pricing varies widely by age, brand, and condition. A basic manual bench comparator or a manual Rockwell tester typically trades in the low thousands, while a CNC video measuring machine or a fully digital hardness tester with working software and current calibration can bring considerably more. If you need a defensible number for insurance, financing, or a purchase decision, KD Auctions provides AMEA-certified, USPAP-compliant appraisals accepted by lenders, courts, and the IRS.

Selling or Liquidating Your Metrology Equipment

Optical comparators, video measuring machines, and hardness testers are some of the most overlooked assets in a shop liquidation. They get lumped into a generic gage-room lot instead of being catalogued individually, and sellers leave money on the table as a result. Because calibration labs, job shops, and independent QC contractors actively shop for this equipment, a comparator or hardness tester listed on its own, with clear photos, model and serial information, and calibration history, typically draws stronger bidding than the same item buried in a mixed pallet lot. If the machine still holds accurate readings, say so and back it up with a certificate, since documented accuracy is often the single biggest lever on the final price.

Auction vs. Cash Purchase

KD Auctions offers two paths for sellers. A managed online auction typically runs 6 to 10 weeks from intake to close and reaches KD's network of 500,000+ industry contacts, which tends to produce the strongest price discovery for specialized or higher-value metrology equipment like CNC video measuring machines. A direct cash purchase is faster: KD makes an offer within 24 to 72 hours, funds typically move 3 to 7 days after you accept, and removal happens within 1 to 2 weeks, which suits sellers on a lease deadline or plant-closure timeline who need certainty over top dollar. Commission on a managed auction is tailored to the engagement and quoted upfront, and most sellers pay nothing out of pocket. KD Auctions has run hundreds of auctions since 1996 and hundreds of millions in machinery sales, so whether your metrology equipment is one lot in a full plant liquidation or the entire sale, there is a process built for it.

FAQ

How much is a used optical comparator or video measuring machine worth?

It depends heavily on age, screen or stage size, optics condition, and whether it carries a working digital readout or CNC control with current software. Manual bench comparators often sell in the low thousands, while CNC video measuring machines with working software and recent calibration can bring considerably more. A certified appraisal is the only way to get a defensible number for your specific make and model.

Does a hardness tester need to be recalibrated after I buy it at auction?

In most cases, yes. Equipment purchased at auction sells as-is, and even a unit with a recent calibration certificate should be verified against certified test blocks once it is installed and running in its new location, since shipping and reinstallation can affect readings.

Can I sell just my QC and metrology equipment through KD Auctions, or does it need to be part of a full plant liquidation?

Either works. KD Auctions handles everything from a single optical comparator or hardness tester to a complete plant liquidation, and metrology equipment is often listed individually within a larger sale to attract the calibration labs and QC-focused buyers who specifically shop for it. Call 480.455.3910 to talk through what you have and which path, auction or cash purchase, fits your timeline.