1133 
10. Diaphragm Gauge Measurements 
The deformations of the steel diaphragms used in the diaphragm 
gauges at various positions aft of the charge are given in Table II. 
(Note that the shot numbers for position A and position B are inter- 
changed from those of piezoelectric gauges due to the diaphragm 
gauges being on the opposite end of the charge from the former.) 
These deformations have been plotted against distance (log-log) in 
Fig. 11, together with the deformation-distance relation for normal 
cylindrical 50 1b TNT charges (ratio of length/diameter = ca. 1.7). 
The relative magnitude of the deformations for the various 
gauge positions with respect to the charge follows the relative 
magnitude of peak pressure (Fig. 8) rather than that for impulse 
(Fig. 9). This is in accord with previous observations at UERL 
wherein the diaphragm gauge deformations on large charges, owing to 
their short response time relative to the time constant of the 
pressure wave, follow peak pressure; for small charges, where the 
response time of the gauge is long compared with the time constant 
of the shock wave, the diaphragm gauge deformations follow the impulse. 
Deformations measured off the non-detonator end of the charge 
(position B) are greater than those off the detonator end (position A). 
Owing to the "piling-up" of the shock wave in position B, the pressure 
averaged over the reaction time of the gauge is thereby greater than 
that in position A. The same effect is noted for double-ended 
detonated charges compared with single-ended detonated charges with 
gauges in the bisecting plane of the charge (position C). 
The slope of the log deformation-log distance curves for the 
positions off the ends of the charge is greater than that for 
positions in the bisecting plane, as the curves were plotted. This 
is probably due to the fact that the distances plotted were as 
measured from the center of the charge (rg + 4/2, or rp + 4/2). 
The gauges off the ends, therefore, are actually nearer the end of the 
charge than indicated, and the difference is relatively greater for 
the gauges closest to the charge, hence the greater slope. If 
deformations for more than two distances were available, this would 
be indicated by an upward curvature of the line at smaller distances. 
When these deformations are plotted against the distance to the nearest 
ends of the charge the slope diminishes to approximately that obtained 
in the bisecting plane (which is roughly equal to that from nearly 
symmetrically shaped cylindrical charges). 
Compared with nearly symmetrical cylindrical charges of equal 
weight, the deformations measured off the ends of the line charges are 
much lower. Line charge deformations are about equal when measured 
in the bisecting plane of charges detonated from both ends. These 
data are in agreement with the piezoelectric gauge results. 
-23- 
