6 
  
Fig 6 
Contact-scale stereogram of calibra- 
tion body used to evaluate the System 
used for the portrayal of textures at 
millimetre scales 
In these observations there seemed to be cor- 
relation between the patterns and senses of 
discrepancies in Z and the positioning of 
gaugeblocks on the (film) gridplate replica. 
Subsequently, stereograms were obtained with 
the same image-acquisition system but with a 
glass gridplate replica. Adjustment to control 
in that case gave standard deviations in both 
X and Y of 0.05 mm and of 0.13 mm in Z. Some 
interesting phenomena were noted in this work 
in the contexts of relationships between 
instrumental settings of principal distance, 
phi settings, orientation procedures and the 
resultant affinity in the model - on which it 
is likely that the pursuit of further inves- 
tigations will justify elaboration in sub- 
sequent publications. 
Microscopic Texture Studies 
Some very preliminary work has been done in 
collaboration with CSIRO on the acquisition 
and evaluation of microstereograms of aggre- 
gate samples, with the objective of portraying 
magnitudes of the order of micrometres, but 
the results of that work do not yet warrant 
presentation. 
This collaboration, however, was initiated in 
the context of studies which had been procee- 
ding in CSIRO for many years, related to the 
geometry of the diamond-tipped indenters used 
for studying the hardness of metals and to 
the geometry of the indentations which those 
tools make. Resulting from this collaboration, 
some results have been presented (Layton, 1978) 
to Technical Committee 5, covering the field 
of Hardness Testing in Theory and Application, 
of the International Measurement Conference 
(IMEKO) in Stuttgart from 16th to 19th May, 
1978, under the Chairmanship of Dipl Ing 
Lambert of the Institution. of German Engi- 
neers (Verrein Deutscher Ingenieure). 
A rather similar procedure was followed in 
107 
that case, to the procedure described pre- 
viously in this paper. A formline plot of a 
Rockwell sphero-cone diamond indenter was pro- 
duced, using 35 mm negatives of photographs 
taken with a Zeiss Jena camera-microscope 
system. In that case, considerable difficulty 
was experienced in observing the highly- 
polished diamond surfaces. That difficulty 
was overcome by using a dulling spray to make 
the diamond surface opaque. 
The formline interval plotted of the Rockwell 
indenter was chosen at a tenth of a millimetre 
at the model scale of the stereoscopic model 
achieved in the WILD A.10 Autograph, which 
was assessed as being equivalent to about 
7.4 micrometres in the object. Calibration in 
that case presented more problems than with 
the macroscopic scales reported herein, as it 
was not practicable to combine both a plani- 
metric and a height standard in the one cali- 
bration body. Nor was it possible to approach 
the principal distance of the image acquisi- 
tion system in the restitution instrument, as 
closely as in the macroscopic case. The affine 
nature of the restitution was thus much more 
pronounced. 
The planimetric calibration body in that case 
was a haemocytometer grid of one millimetre, 
with a grid interval (observed) of 200 micro- 
metres. The standard deviation of the 36 points 
observed in that calibration body gave results 
in X, Y, and 2, respectively of 1.4, 1.2 and 
1.3 micrometres in the object, which was be- 
lieved to be accurate to within 0.2 micro- 
metres. 
While the illustration of the equipment and 
stereograms used for those studies is not con- 
sidered warranted in this paper, exhibition 
of such material should be possible at the 
time of presentation. And perhaps, by that 
time, some further results may have been 
achieved with aggregate samples.