end, the instruments are ranked with the best choice having 
the highest numerical evaluation. 
leaking Pagjtst fpy An3lyti.ca.l Instruments 
Originally, the document on testing was envisioned as a 
set of standard procedures for accuracy testing for all 
analytical instruments, but just as in the case of 
establishing standards and specifications, much shadow 
boxing was done before the first document was produced. The 
testing procedure adopted for accuracy testing was one 
proposed by Larry Fritz for calibrating comparators, and it 
is based on making multiple readings by several operators 
on a grid plate containing five rows and five columns of 
grid intersectionse Each operator observes the grid plate 
several times at four 90° rotations of the plate. The end 
result is an evaluation for each operator, the grid, and 
the instrument. Calibration parameters are computed for use 
in correcting instrument coordinates, even in real-time 
correction of analytical stereopiocter coordinates. 
The theory behind this approach to evaluating 
analytical instruments relies on the assumption that if the 
instrument contains inherent accuracies in measuring 
coordinates, then overall accuracy follows. However, this 
approach leaves many components untested, including the 
software and firmware. A task group within the Working 
Group under the direction of Dr. Anita Laiho, Helsinki 
University of Technology. Finland, is revising parts of the 
present manual and preparing recommendations for future 
Working Groups. 
USER/MANUFACTURER SURVEY FOR PROBLEM AREAS 
One of our most important assignments is to survey 
users and manufacturers to identify areas where future 
Working Groups Il/l can help most. The Task Group for this 
objective under the leadership of Mr. Roger R. (Sky) 
Chamard. 5. Coyote, is to make this survey and prepare a 
report of recommendations. 
DISTRIBUTION 
Updated versions of the existing documents and the 
table of manufacturers are not scheduled for completion 
until the end of 1991} but the current versions are 
available free of charge with the exception of the catalog 
of analytical instruments which is not available at all.