investigation was undertaken with the objectives of, (1) Gaining the best possible
understanding of carbon black morphology, (2) Developing techniques which could be
on Micro- semi-automated for speedy acquisition of considerable data, and applicable on simi-
| opened lar ultra microscopic objects. The photogrammetric technique appeared as the most
tions. promising one for high accuracy quantification in three dimensions.
ses.
. about | The current generation photogrammetric instruments are capable of such high accu-
volume, rate 3-D measurements and, in their computer interface mode, can accomplish the
ng but necessary data reductions including, when desired, contour mapping. In establish-
ing the photogrammetric techniques, one finds that the stage plate containing the
specimen in both TEM and SEM has generally four orientation elements, viz., (1)
re of the Uniaxial tilt around X- or Y-axis (corresponding to or 9 tilt in conventional
through photogrammetry); (2) Rotation around the direction of the principal electron axis
display- (similar to K-rotation in conventional photogrammetry); (3) X-translation; and
ce featu- (4) Y-translation. In a relative sense, assuming no movement of the specimen,
these correspond to the following exterior orientation parameters: 0 or $; k ; bx
and by, respectively. There are, however, limitations in each of these elements
The elec- peculiar to the various TEM's and SEM's.
er.the
Screen, By using rigorous and statistically controlled calibration procedures, it has been
urface observed (see Ghosh and Nagaraja, 1976) that
e of sub- l. An electron microscope system is represented better by a mathematical model
S. for an effective central (perspective) projection rather than for parallel
projection. This, however, is not found to be statistically significant at
on extrac- magnifications above 2000x, for generally desired high accuracy.
uld supp- 2. The collinearity condition is disturbed by systematic distortions of four
m. types, viz., Scale, Spiral, Tangential and Radial. Of these, for most appli-
cations, the tangential distortion can be effectively contained in the math
mely fine model of the spiral distortion; and the scale distortion can be contained
ch may directly in the math model for the projection (perspective or parallel).
ustry 3. The effects of these distortions are best corrected by the use of polynomials
particle applied sequentially.
in end 4. The degree of stability of the electron microscope system has been found to
ers is be of significant influence on the distortions and the reliability of the used
construct- math models. Therefore, evaluation of such working systems is imperative.
cation of
s impera- In view of the above, in order to define quantitatively the spatial configurations
and volume estimations of carbon black primary aggregates, an investigative rese-
arch was performed, amongst other tasks, to : (1) Determine the optimum magnifica-
American tion and convergent (parallactic) angle for generating stereo-models to be used in
on) pro- subsequent studies; and (2) Mapping of carbon black aggregates by combining TEM
ack. and SEM.
new pro-
The following instrument systems were involved in these studies
A. TEM : Philips model EM200,0wned by Ashland Chemical Co.;
it'is B. SEM : Coates & Welter model 100-4, owned by Ashland Chemical Co.;
studies C. Wild A7 autograph, owned by the Ohio State Univ. Dept. of Geodetic Science;
two-di- D. Zeiss PSK stereocomparator, owned by the OSU Department of Geodetic Science;
alyzer E. Photogrammetric Plotting System (PPS) developed at the Ashland Chemical Co.
derived facilities. This comprises a Zeiss Stereocord with Direc 1, a Hewlett-Pack-
ard programmable desk-top calculator model HP9825A, and a Hewlett-Packard
plotter model HP9872A (capable of plotting in four colors);
pelieved F. IBM 360/75 computer system owned by the OSU Computer Center; and
ents of G. A replica grid (from a diffraction grating) having 2160 lines per mm, owned
3 recog- by Ashland Chemical Co., manufactured by Ernest E. Fullam, Inc.
but the
