Thomson Precision Balls Metrology LabThe Thomson Precision A2LA and ISO 17025:2005 accredited metrology laboratory offers a unique blend of controlled environment, state-of-the-art measuring equipment and highly proficient Laboratory Technicians to deliver service and accuracy you can depend on. Our scope of laboratory accreditation includes circular geometry (sphericity), spherical diameter and (spherical) surface. Our commitment to quality is underscored by our prestigious customer base that includes world-class ball manufacturers, other calibrators and measuring equipment manufacturers. Our expertise in calibrating spherical masters is unsurpassed in the industry.
How Can Our Lab Help You?If you are a ball manufacturer in need of a Master Ball Set or calibration of your existing Masters – Thomson brings more than 25 years of experience measuring and calibrating spheres. If you are an OEM gauge manufacturer and need Standards by which to verify your equipment – Our Master Balls are calibrated at NIST and have direct traceability. If you are a manufacturer using a coordinate axis-measuring machine (CMM), and the check standard is a ball bar - Only an ISO 17025 accredited calibration laboratory, whose scope of accreditation includes spheres, can be used to calibrate that sphere. The manufacturer of the ball bar may have supplied a calibration “cert” for that sphere, but unless the manufacturer is ISO 17025 compliant (and their scope of accreditation includes spheres), their certificate does not meet the requirements of ISO/TS 16949 as a calibrator. Thomson Precision Metrology Lab is accredited by A2LA to measure spherical geometry (spheres). How To Determine CompetencyA good indicator of competency for a calibration laboratory is the degree of uncertainty that lab is able to demonstrate. Danaher Motion’s metrology lab demonstrates a Best Uncertainty of:
How Do We Achieve These Results?Our laboratory comparison masters are Tungsten Carbide and have been calibrated by the National Institute of Standards and Technology (NIST) for minimum uncertainty and maximum accuracy. Our gage environment is controlled to be between Class 1000 and Class 10,000 cleanliness levels and temperature is regulated to +/- 0.5 degrees Fahrenheit. Calibrating DiameterWe measure diameter in accordance with the requirements of ABMA Standard 10 and/or ISO 3290. The instrumentation system consists of proprietary gage amplifiers operating at a range of +/- 0.001 inches with a resolution of +/- 0.000001 inches. The gage heads are mounted on precision comparator stands with a capacity of over 9 inches. The stands have rugged bases for stability and the gage heads are mounted units which allow friction free straight-line motion. The specimen balls are positioned in custom crafted fixtures that assure the ball will return to the same gage location for each reading. This minimizes any adverse effect of surface condition or parallelism.
Calibrating Ball SphericityWe measure ball sphericity (roundness) using a Mahr-Federal Formscan 3100 Circular Geometry Gage. This system uses a design specifically engineered to gage spheres. The holding system for this measurement will accommodate balls from 0.020 inch diameter to 10.00-inch diameter, with the appropriate fixturing. The active elements of the gage system are engineered to minimize any vibration. Calibrating Surface FinishWe calibrate surface finish on state-of-the-art Taylor-Hobson SP3 Talysurf surface-finish measuring equipment. This equipment is mounted on a vibration isolation table. The standard stylus is conical diamond. However, surface finish metrology is limited only by the ingenuity of the holding fixture. Our gage travel is limited to 50mm. The wavelength of the roughness filter can be as small as 0.0001 inches or as large as 1.0 inches. We are able to evaluate surface finish in as many as 27 different surface finish parameters. The resolution is approximately four nm, which is only one nm less than the resolution NIST uses to measure surface finish. A NIST calibrated Tungsten Carbide check standard is used to verify the continued performance of the instrument. |