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1

Evaluation of CMM for flatness measurements

Sidki H. M., Amer M.

Metrology and Measurement Systems

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2008

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Vol. 15, nr 4

585-593

EN

Coordinate measuring machine (CMM) is a universal measuring instrument in dimensional metrology. However, the CMM has many sources of errors and deviations that affect its precision and accuracy. Unfortunately, the accuracy of flatness measurement by the CMM is not studied which is very important feature in metrology and industry at present time. A method is introduced to evaluate the accuracy of the flatness measurement of the Zeiss CMM based on flatness measurement of an optical flat. The flatnesses of the optical flat are measured by four different techniques using the CMM. Moreover, the effects of CMM head probe's scanning speed and step width on flatness measurements are examined separately in special measuring subroutines. The flatness of the optical flat surfaces are calibrated using Zygo phase shifting interferometer since it is used as reference for this study. The experimental results show that the CMM's probing points technique can be used for accurate measurements of flatness.

2

Calibration of reference standard quartz rotating plates

Sidki H. M., Amer M., Abd El Aziz F.

Metrology and Measurement Systems

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2006

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Vol. 13, nr 4

383-394

EN

An accurate linear polarized optical system for calibrating the quartz plate angles is introduced in this work. The quartz plate parallelism and surface roughness are measured using a phase shifting laser interferometer to study their effects on quartz rotation angles which equals to š18.21 sec. A polynomial regression method is applied to determine and extrapolate quartz rotation angles corresponds to the uncalibrated regions of the visible spectrum. The bi-rotation index values (nL - nR) of the quartz plates for all scanned wavelengths are determined applying the calibrated rotation angles. The uncertainty of the calibrations is evaluated, also the combined uncertainty of calibrations for angles (Δβt ≈ š0.09°) that shows the usefulness of this article.

3

Angle measurement of right angle prisms using optical coordinate measuring instrument

Sidki H. M.

Metrology and Measurement Systems

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2005

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Vol. 12, nr 4

449-462

EN

A new technique for calibrating the angles of right angle prisms using an optical coordinate measuring instruments is presented in this work. The technique is an optical non-contact method that is based on focusing of images of the measured elements. Measurements of the angles of optical components are very important since they affect the accuracy and precession of the measuremet techniques. The results and their uncertainties show the validity of the method.

PL

W tej pracy zaprezentowano nową metodę pomiarów kątów pryzmatów prostokątnych wykorzystującą optyczą współrzędnościową maszynę pomiarową. Jest to optyczna metoda bezkontaktowa, która opiera się na ogniskowaniu obrazów mierzonych elementów. Pomiary kątów elementów optycznych są bardzo ważne, ponieważ mają wpływ na dokładność technik pomiarowych. Uzyskane wyniki i ich niepewności potwierdzają poprawność metody.

4

The use of laser interferometer for calibration of rotation errors of coordinate measuring machine

Sidki H. M., Zahwi S. Z.

Metrology and Measurement Systems

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2002

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Vol. 9, nr 1

45-53

EN

Coordinate Measuring Machines (CMM) are now widely used in industry, metrology and production engineering. The errors of CMM affect its accuracy. One of the most serious errors of the CMM is its rotation errors. This error is produced during the movement of the CMM subassemblies, and is generated from errors of form and errors in pneumatic and mechanical systems. Rotation errors are very difficult to be determined without an accurace reference measuring system. The use of laser interferometer reference measuring system is one of the most convenient methods for this purpose due to its high accuracy, repeatability and the possibility to compensate for the errors resulting from the variations of temperature and humidity during the measurement. The procedure described in this paper shows an accurace and precise method to calibrate the CMM rotation errors using laser interferometer.

PL

Współrzędnościowe Maszyny Pomiarowe (WMP) są obecnie szeroko stosowane w przemyśle, metrologii i inżynierii produkcyjnej. Błędy WMP mają wpływ na dokładność realizowanych pomiarów. Jednym z ważniejszych błędów WMP są błędy rotacyjne charakteryzujące kątowe przemieszczenia ruchomego ramienia maszyny wokół osi x, y, z. Błędy rotacyjne są trudne do wykrycia bez użycia dokładnego sprzętu pomiarowego. Użycie do tego celu interferometru laserowego jest jedną z najbardziej wygodnych metod ze względu na jego wysoką dokładność i powtarzalność oraz możliwość kompensacji w czasie pomiaru błędów pochodzących od wpływu temperatury i wilgotności. Przedstawiona w publikacji procedura opisuje dokładną metodę oceny błędów rotacyjnych WMP za pomocą interferometru laserowego.