The Guyson Corporation in Saratoga Springs, New York, has introduced a surface roughness gauge, based on a third party certified “Master Specimen” of non-periodic Ra standard. These specimens are produced using a one pass blasting method and are quantified as per ASTM D7127.
The “Guyson Institute of Standards” (GIS) was created by Guyson, with the sole purpose to define the Ra finishing standards for non-periodic finishes for the blast finishing industry. Until now most roughness certified coupons were made to reference a periodic machine surface. A periodic surface is one that has a repeated pattern created by a machine cutting blade moving back and forth. Blast finishing is a nonperiodic process and its Ra value should not be determined with a periodic specimen which will give an inaccurate result.
Previously, a nonperiodic blast specimen did not exist, creating a problem when determining a precise roughness value on a profilometer. This added to the inconsistencies in the results. The new blast specimen created by the Guyson Institute of Standards determines a specific Ra value on a calibrated profilometer which will enable the user to correctly match that Ra Value on a product finish. All previous Ra measurements up to this point, are inconsistent because there was no scientifically certified specimen to determine the gloss value of a non periodic finish.
Guyson has a Patent Pending on this product, and is available only through Guyson Corporation. If your product involves people’s welfare, now you can make sure that you have all your specifications defined and certified,” stated Steve Byrnes, President of Guyson Corporation. “With the Guyson Institute of Standards blast specimen, you have a scientifically accurate starting point for the Ra finish you want on your product.”