Asq Z1.4-2008 Pdf Free |TOP| 32 ⏭


Asq Z1.4-2008 Pdf Free 32

ReferencesDineen, D. and Koedwagh, C. 1997. ANSI Z1.4 Manufacturing Guidance for Secondary Inspection – Improving the performance of the secondary inspection process. Part 1 – General. A joint task from the ANSI Z1.4 committees in North America and Europe.21.3, October, 1997

Buhrmester, P. and Dineen, D. 1994. An endpoint certification tool for secondary inspection of high performance, non-contact checking instruments in the fulfilment of the international ANSI Z1.4 scheme. Int. J. Quality Models. 14, 1·4, pp. 23-36.

The dual energy linear scanner normally used for export inspection is also employed for the secondary inspection process. Typically, the energy of the beam used tomachine the alloy is set at 14 kV, and the energy used tocheck the billets is 5 kV. Because delays in inspecting the billets are less than for the alloy, a lower energy beam is normally used to machine the billets. Varying the voltage levels for the upper and lower energies can be done easily. This affects the Z scan and window, sometimes to the detriment of the energy scan. Because the system is very sensitive to fluctuations in the upper energy, the survey should be done using the lowest upper energy possible and, in general, it is best to not use the 9 kV upper energy if possible. The energy spread of the 9 kV beam, in addition to those already mentioned for the 14 kV beam, is +/-400 eV, and this can result in changes in the spectrum of the beam during a survey depending on the values used in the system. Because this spread can cause problems with the imaging, it is best to use a fixed upper energy of 5 or 7.5 kV for the Z scale. The energy window should also be restricted not to exceed 5 kV. The use of a lower energy for the secondary inspection is also feasible provided that the system is managed correctly and the survey is not excessively delayed.