FEDERAL SPECIFICATION – GGG-P-463CSpecification for use in precision locating, layout and inspection worksGGG-P-463CFederal Specification for granite comes under, GGG-P-463C. This specification was approved by, The commissioner, Federal supply service, General service administration. For the use of all federal agencies. Scope:This specification covers igneous rock (granite) surface plate for use in precision locating, layout and inspection […]

DIN – 876Scope:This standard applies to natural hard rock surface plates, which are used as a plane, or datum surface in dimensional metrology, in particular in testing for deviations of form or position. Material and finish:The surface plate should be made from natural hard rock, sound, free of flaws, close grained and of uniform texture, […]

GRANITE SURFACE PLATES – SPECIFICATION – INDIAN STANDARD -IS7327: 2003The Bureau of Indian Standards adopted this Indian Standard, after the draft finalized by the Engineering Metrology Sectional committee had been approved by the Light Mechanical Engineering Council. This standard was originally published in 1974 and in its preparation considerable assistance had been derived from the […]

ISO 9001 : CALIBRATION OF MEASURING INSTRUMENTSISO9001ISO 9001 certified organisations have to make decisions regarding where to send their measuring instruments for calibration. Nowadays, many calibration laboratories have got accredited to ISO 17025. Also, many accredited laboratories are not accredited for all the services they offer. The use of non-accredited calibration labs, or non accredited […]

DISCUSSION ON CALIBRATION AND MEASUREMENTMaking a measurement is simple. We have all done it. But making measurements, in which we have a quantifiable level of confidence , is not a trivial task. Achievement of a measurement that can be compared with confidence with other measurements, possibly made in a different country, is even more difficult. […]

CALIBRATION PROCESSESObtaining a calibration in which we have confidenceCALIBRATIONAs mentioned above, to calibrate an electronic manometer we can borrow, purchase or hire a similar or superior manometer and a pressure source, and perform a comparison of the two manometers over the pressure range of interest. Our recent experience in measuring a pressure that appears to […]

APPLICATION OF LAPPING PROCESS ON GRANITE Lapping process on granite is a working process, during which workpiece and tool slide over one another on a lapping compound and are subject to continually changing direction of rotation. Stock removal occurs as a result of the rolling and sliding action of abrasive grains (aluminium oxide, silicone carbide, […]

METROLOGY – SYSTEMS OF MEASUREMENT A system of measurement is a collection of units of measurement. Systems of measurement have been regulated and defined for the purposes of science and commerce. Systems of measurement in modern use include the Metric System, the Imperial (English) System, and The International System of units (SI). LINEAR MEASUREMENTS Comparisons […]

CUTTING TOOLS – CUTTING SPEED – GUIDE This cutting tools and cutting speed trouble shooting guide will help you with common problems faced during machining. Reference Cause Remedy Excessive flankwear  Cutting speed too high,Infeed per pass too small-or too many passes,Infeed method incorrectIncorrect carbide grade – Reduce the cutting speed– Also, increase the cutting depth […]

TYPES OF GRANITE USED IN METROLOGY Types of granite used in metrology include Diorite, Gabbro, Rhyolite Porphyry, Intrusion Breccia, Diabase Dykes and Dolerite. DIORITE Diorite is a medium-grained intrusive igneous rock consisting mostly of andesine plagioclase and pyroxene, and small amounts of hornblende and biotite. It is the intrusive equivalent of andesite. Therefore, a medium-grain diorite contains black hornblende […]