Modern Measurement

Extensive measurement from Helmholtz and Holder is the standard physical account. It gives a ratio scale. Stevens introduces interval and ordinal scales. Scott and Suppes give a representational foundation to Stevens’ scales. Suppes, Zinnes, Luce and Narens analyse meaningfulness.

Pletharrays for aeroacoustic phased array applications

“Pletharrays” are introduced, motivated, and presented for application to aeroacoustic phased array measurements. Pletharrays contain a plethora of arrays composed from a modest to high number of array elements to field a remarkably large number of high element count arrays for use in noise source imaging applications. Pletharrays that have been deployed for closed jet transonic wind tunnel, static engine ground, open jet wind tunnel, and flyover phased array tests are presented. Tremendous array element leverage to provide extensive measurement flexibility and fidelity are demonstrated.

Measurement and assessment of out-of-round electric locomotive wheels

This paper presents a detailed investigation of out-of-round electric locomotive wheels through extensive measurement conducted at field sites. More than 2000 wheels, of seven types of locomotives widely used in China, have been measured since April 2013. The measurement results indicate that two types of freight traffic locomotives suffer serious polygonal wear problems with center wavelengths ranging from 160 to 315 mm. The dominating wavelength is 200 mm. Therefore, the investigations are mainly focused on the two locomotive types. The other types, which are taken for comparison, do not exhibit obvious polygonal wear. However, they exhibited more or less eccentricity. The effect of wheel re-profiling on the wheel polygon is also investigated and discussed. The dominating harmonic orders and center wavelengths after re-profiling are consistent with those before re-profiling at the correct circumstances, if the center wavelength of the polygonal wear is about 200 mm.