622 
Bottom View 
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Nut Stud 
Housing 
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Top View 
TMB 9079 
Figure 4 - Modification of Quartz Gage for Attachment to a Surface 
A nut is soldered to the bottom of the housing. and a threaded stud is soldered 
to the surface at which the pressure is to be measured. 
A brass nut whose outside diameter is the same as that of the pan, 1/2 inch, 
and whose inside diameter is 1/4 inch, is silver-soldered to the bottom of the 
housing. Since this nut is only 0.08 inch thick, it does not add excessively 
to the size or mass of the gage. A brass stud 1/4 inch in diameter and 0.075 
inch thick is threaded to fit the nut. This stud is soldered to the surface 
under investigation, and the gage is then screwed down securely over the stud. 
Figure 4 shows the brass mount before and after adaptation to the surface type 
of gage, together with the nut and stud used in the conversion. 
This type of "surface gage" has been designed so that it can be 
firmly attached not only to a rigid surface, but also to the surface of a dia- 
phragm subjected to explosive loading. In the latter case the brass-plate 
type of tourmaline gage illustrated in Figure 6, on page 9, is inapplicable, 
as it is much too massive. 
