Brunson Instrument Company

A Blog for Metrology Enthusiasts

Would you drive a Ferrari on bald tires?

Would you drive a Ferrari with bald tires?Then why make the same mistake with your Laser Tracker?

Most of us have heard the proverb that ends, "For want of a battle the kingdom was lost. And all for the want of a horseshoe nail." While most companies have moved beyond horseshoes to the high-tech realms of lasers, the failure of the most inconsequential-seeming part of your equipment can destroy your entire measurement operation.

The modern nail

A case in point is a "target holder," "nest" or "SMR holder" for your laser tracker. Laser trackers are essential tools for many industries, including aerospace and automotive. You can use these high-tech measuring devices not only for inspection, but also to provide data on the wear or movement of tools and fixtures over time, highlighting critical trends relevant to your quality plan.

Brunson laser tracker target holdersA commonly used target device is a spherically mounted retroreflector, known as an SMR. The fixture, or target holder, that holds SMRs in place are as vital to your system as the SMR itself. You may have made a considerable metrology investment ranging from $60,000 to $300,000 in your laser tracker, and $1,000 - $5,000 for the SMR. The target holder is the least expensive component, running about $50 - $300.

A target holder is often regarded as a commodity, like tires on a car. If the target holder is of less than the highest quality, the accuracy of your measurements will be compromised. Using low quality or out-of-spec target holders makes as much sense as driving a Ferrari on bald tires. Don’t fall prey to this commodity mentality! We have seen customers who toss their target holders into a box or drawer like discarded nuts and bolts. This will damage the target holder and the resulting measurements.

Target holders you can trust

We've been designing and manufacturing target holders since 2002. Our engineers and manufacturing team ensure that our target holders are high precision for use with discerning instruments. Understanding the critical nature of target holders is essential to providing the best laser tracker measurement performance possible. Here is an example of our standard tolerances:

  • Offset +/- 0.0005" (+/0.013 mm)
  • Shank diameter -0.0001" to - 0.0005" (-0.003 mm to -0.013 mm)
  • Target centering +/-0.0005" (+/-0.003 mm)  

For customers who desire NIST traceable certifications and serialization of each target holder, SNC (serialized and certified) is an available option that includes permanently engraved serial numbers. This allows you and your staff to be assured of the accuracy of your measurements week after week by knowing that the same nest was used.

Brunson Target Holders for Laser TrackersWhen target holders are serialized and/or certified you are provided with documentation of their precise dimensional data and a recertification date. Our certifications are NIST traceable, to guarantee not only our target nests' reliability, but also their traceability. By using the recertification date, you can prepare in advance to evaluate your target holder and make sure that its accuracy will not deteriorate. Your quality team can enter both serial numbers and recertification dates into a database to generate automatic oversight of target holder dimensions.

Hitting your quality target

A Ferrari with bald tires runs off the road.

A laser tracker using poor quality or out-of-spec target holders compromises the accuracy of 3D measurements.

Whatever target holder requirements you have, Brunson is here to make sure you get what you need. Contact us now to achieve the highest confidence in your laser tracker measurements through high precision target holders.


Jim Vaughan
By Jim Vaughan on Jan 18, 2019 3:22:30 PM

Topics: Metrology, laser tracker, smr, target holder, ccr, 3d, measurement

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The Brunson blog is designed to be a platform for collaborative exploration in the field of metrology. You can expect to explore new Brunson products, hear from industry professionals invited to be contributing editors, and gain insight from customers who use Brunson products. So if you are one of the chosen few people who understand that Metrology is not a study of the weather, please join us here.