Martin diameter

Several diameter definitions are used in particle image measurements (Fig. 7). Martin diameter, the chord length which divides the projected particle into two equal areas with respect to a fixed dkection (29) Feret diameter, the projected length with respect to a reference dkection (30) and the diameter of equivalent surface area, the diameter of a ckcle the area of which is equivalent to the projected area of the particle in question (3). 

Fig. 7. Definition of diameteis frequently used in image analysis (a) horizontal Martin diameter, (b) horizontal Feret diameter, and (c) diameter of equal...

FIG. 1.10 Characterization of the size of irregular particles (a) a schematic illustration of Martin diameters, (b) the use of a graticule to estimate the characteristic dimension. 

Select a field containing about 10 particles from Figure 1.12b and measure the Martin diameters of the population parallel to the bottom of the micrograph (a photocopy can be made and... 

Perimeter, Hausner shape factors, Martins diameter, Feret diameter, two dimensional sphericity, rugosity. 

Martins Diameter A statistical particle diameter the length of a line drawn parallel to a chosen direction such that it bisects the area of a particle. The value obtained depends on the particle orientation, and so these measurments have significance only when a large enough number of measurements are averaged together. See also Feret s Diameter. 

For irregularly shaped particles, the diameter of a particle may be estimated using one of several methods Feret diameter, Martin diameter, projected-area diameter, equivalent diameter, or aerodynamic diameter. The two most commonly used diameters, the Feret and Martin diameters, are relative to a randomly chosen reference line, typically the bottom edge of the viewing frame, where the Feret... 

There is a confusing array of measurement options in modem digital image analyzers. Besides area and perimeter, it is possible to obtain measurements of geometrical features such as equivalent circular diameter, aspect ratio, shape factors, Feret diameters, Martin diameters, to name just a few. In most instruments, the operator has the flexibility to design his or her own geometrical property using the built-in measurements in some mathematical combination defined by the... 

Every measured value of fraction of one powder Mode of particle size distribution Equivalent Martin diameter (L)... 

The Martin Diameter, dy, is also a statistical diameter defined as the mean chord length of the projected outline of the particle, which appropriately bisects the area of the projected profile, as shown in Fig. 1. Like the Feret diameter, the Martin diameter is also employed most often during particle characterization using the optical imaging technique to be discussed later. 

Figure 1 Illustration for projected area diameter, Feret diameter, and Martin diameter.

Based on the experimental evidence, on the average, the Martin diameter is usually smaller than the mean projected diameter and the Feret diameter larger. Since both Martin and Feret diameters depend on the particle shape, the ratio of Feret diameter to Martin... 

---