The gauge block handbook Episode 8 docx

... light wavelength to the block length the accuracy of the wavelength is of primary importance. The gauge block temperature is measured so that the block length at 20 ºC, the standard 102 during ... Square style blocks, such as the NIST long blocks, are positioned so that the gauge point is at the right in the viewing field of the interferometer. One to fou...

Ngày tải lên: 12/08/2014, 08:21

... fixed gauge, and the required accuracy of the gauge is 0.5 µm. If the size of the gauge requires a stack of five blocks to make up the nominal size of the gauge the accuracy of each block must ... 2.1 (from B89.1.9). Figure 2.1. The length of a gauge block is the distance from the gauging point on the top surface to the plane of the platen adja...

Ngày tải lên: 12/08/2014, 08:21

... only the 30 to 60 mm of the block near the surfaces. For blocks under 100 mm this is the entire block, and there is no problem. For longer blocks, there is a variable amount of the block in the ... If there is a burr on the block or platen, if there is particle of dust between the block and platen, or if the block is seriously warped, the entire face of the...

Ngày tải lên: 12/08/2014, 08:21

... laboratory has a gauge block measured at NIST every year for nine years, it is good practice for the lab to use the mean of the nine measurements as the length of the block rather than the last reported ... either the S block or the C block as the known length (restraint) for the comparison. This permits customer blocks of different materials to be calibrated...

Ngày tải lên: 12/08/2014, 08:21

... through to the gauge block surface G and the platen surface P. The other beam (reference beam) is directed through the compensating plate I to the plane mirror R. The beams are reflected by the surfaces ... σ tot , on gauge block length. 95 The optical path beyond the slit is inside a metal enclosure with a large door to allow a gauge block platen with gau...

Ngày tải lên: 12/08/2014, 08:21

... often in the first part of the scheme. This allows block A to have a different thermal handling than the other blocks which can result in a thermal drift which is not the same as the other blocks. ... temperature. The usefulness of drift eliminating designs depends on the stability of the thermal environment and the accuracy required in the calibration. In the NIST...

Ngày tải lên: 12/08/2014, 08:21

... 1 38 Step 1. The test and slave blocks are wrung down to the same platen and measured independently. The two lengths measured consist of the mechanical length of the block, the wringing ... etc. If a check standard block is used it can be assigned to any of the unknown block positions. The name of the design is simply the number of blocks in the design and the...

Ngày tải lên: 12/08/2014, 08:21

... 86 x 10 -8 chrome carbide block V 2 = 43 x 10 -8 diamond sphere α = 2.231 * (1/3) 2/3 * (86 x 10 -8 + 43 x 10 -8 ) 2/3 * (6) -1/3 (D.5) = 0.000070 mm = 0.070 µm Thus the ... the calibrated block is given by: L u = M u - M s + L s + (α s - α u ) (D.6) where L u is the calibrated length of the unknown block, M u is the measured value of...

Ngày tải lên: 12/08/2014, 08:21

... fixed gauge, and the required accuracy of the gauge is 0.5 µm. If the size of the gauge requires a stack of five blocks to make up the nominal size of the gauge the accuracy of each block must ... 2.1 (from B89.1.9). Figure 2.1. The length of a gauge block is the distance from the gauging point on the top surface to the plane of the platen adja...

Ngày tải lên: 20/06/2014, 18:20

... to the other end of the block, as shown in figure 2.1 (from B89.1.9). Figure 2.1. The length of a gauge block is the distance from the gauging point on the top surface to the plane of the ... If there is a burr on the block or platen, if there is particle of dust between the block and platen, or if the block is seriously warped, the entire face of...

Ngày tải lên: 27/06/2014, 18:20