Accredited Gage Block Calibra tion Service In accordance with: ISO 17025 ANSI/NCSL Z540-1 ISO 10012-1 former MIL-STD-45662A Master Calibra tion The calibration procedure is regarded as a process to be controlled and monitored using SPC techniques. Information that would enable the analysis of control data is to be recorded and can be made available to the user upon request (at extra cost). A second master, sometimes referred to as a control block, is used in the calibration. The purpose of the second master is to generate known difference reading which can be analyzed. The average of the known differences of several readings of the two masters and the range of their differences can be analyzed using statistical techniques. The calibration process can be demonstrably controlled. Reported measurement uncertainties based upon a 95% confidence level (two standard deviations) are dynamic, reflecting the current performance of the specific equipment and operator. Other factors included in the stated uncertainty are derived from a detailed error analysis.  The error analysis is based upon experimentation whenever possible or industry consensus from estimates derived from NIST publications. Experimental checks of the stated uncertainty levels are made using laboratory comparison techniques involving both internal repeatability studies and external comparisons with other calibration laboratories. Our Reference Gage Blocks are calibrated directly by NIST. All other referencestandardsareperiodicallycheckedandcalibratedeitherbyNIST or NVLAP accredited laboratories. Documented histories are maintained. Statistical methods are used to control all of our master gages. Labora tory Calibra tion Each block calibrated using our Laboratory Calibration procedure is calibrated three times using our Master Calibration procedure as described above - Using different transfer master blocks, operators and equipment when possible for all three measurements. The results are averaged together and reported.This results in the lowest possible uncertainty reported to the user as random errors in the measuring process are averaged out. This calibration service is restricted to Webber rectangular croblox® gage blocks of Webber grades LM or AA, GGG grades 0.5 and 1, and B89 grades 00 and K. Commercial Calibra tion Calibrations are performed using the same program as our Master calibrations except that the second master, the control block, is omitted. By omitting this control block some of the statistical tests are also omitted which results in larger uncertainty. All necessary information to confirm the calibration is recorded. All raw data from the comparator, the temperature of the blocks, the temperature of the comparator, and the relative humidity of the surrounding environment is recorded for each measurement. Applied correction factors are broken down and are recorded, as well as the results of any calibrations. Our Reference Gage Blocks are calibrated directly by the National Institute of Standards and Technology.All other reference standards are calibrated either by NIST or NVLAP accredited laboratories.Documented histories are maintained of our measuring and test equipment. Statistical methods are used to control our Master Gage Blocks. Reported uncertainties are based on a 95% confidence level. Experimental checks of the uncertainty are made using laboratory comparison techniques involving repeatability studies and external comparisons with other calibration laboratories. NOTICE: Webber Gage cannot recommend recalibration due dates on our calibration certificates or calibration stickers. Recalibration due dates must be provided to us at the time of order. If this information is not provided, the recalibration due date will be left blank for the user to add. NVLAP LAB CODE 200038-0 Approximate Best Uncertainty (k=2) for blocks through 4" (100mm) in length Grade Commercial Calibration Master Calibration Laboratory Calibration Uncertainty Minimum Uncertainty Minimum Uncertainty Minimum Webber LM 0.65 + 0.7L 1.4µin GGG 0.5 .016 + .0007L .035µm Webber AA B89 Grade 00, K 1.6 + 1.0L 2.4 µin 1.2 + 0.7L 1.7µin 0.65 + 0.7L 1.4µin GGG 1 .04 + .001L .060µm .03 + .0007L .045µm .016 + .0007L .035µm Webber A1 B89 Grade 0 2.0 + 1.0L 3.0 µin 1.8 + 0.7L 2.0µin GGG 2 .05 + .001L .075µm .045 + .0007L .050µm B89 Grade AS1 2.0 + 1.0L 3.0 µin 1.8 + 0.7L 2.0µin GGG 3 .05 + .001L .075µm .05 + .0007L .050µm NVLAP® accreditation does not constitute an endorsement of any product by NVLAP® or any agency of the U.S. Government. 406 S t arrett -W ebber G age B locks