Miniature pressure transducer responds to static or dynamic pressures acting against a structural surface without introducing errors caused by stresses in the structural surface. This is accomplished by a thin stainless steel pressure sensing diaphragm with an attached foil strain gage

Walker, R. R.

Wickham, C. G.

English

NASA Technical Reports Server

Strain (iage
	 Terminal Board Strain Gage Pattern 
July 1968	 Brief 68-10246 
NASA TECH BRIEF 
NASA Tech Briefs are issued to summarize specific innovations derived from the U.S. space program, 
to encourage their commercial application. Copies are available to the public at 15 cents each 
from the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Miniature Pressure Transducer for Stressed Member Application 
A miniature pressure transducer has been designed 
and fabricated in such a way that it responds to static 
or dynamic pressures acting against a structural sur-
face without introducing errors caused by stresses in 
the structural surface. This is accomplished by a thin 
stainless steel pressure sensing diaphragm with an 
attached foil strain gage. The strain gage is bonded 
to the stressed surface and has a very thin profile and 
low mass. 
A metal film strain gage is installed on the inner 
surface of the housing diaphragm by conventional 
strain gage application procedures, using hard epoxy 
adhesive. Gold-plated wires 0.001 inch in diameter are 
soldered to the three tabs of the strain gage element. 
These wires are passed through holes in a miniature 
terminal board that is bonded to a land at the center 
of the transducer housing. The 0.001-inch diameter 
wires are each soldered to one end of the terminal 
element. Larger (0.019) lead-in wires are soldered to 
the other end of each terminal element and passed out
through the access hole in the transducer cover plate. 
The cover plate is then joined to the transducer hous-
ing by an overlapping spot-weld process using a ca-
pacitor discharge welder. The void between the cover 
plate and terminal board is filled with epoxy to afford 
maximum protection for lead wire ends and to provide 
a seal for the back side of the transducer. 
Notes: 
I. Zero balance of 4 transducers tested did not deviate 
more than 0.03°,, of full scale per °F over a tem-
perature range of 32 0
 to 120°F. Sensitivity of the 4 
transducers remained within 0.47° c
 of their respec-
tive full scale room temperature outputs over the 
same temperature range. 
2. Inquiries concerning this innovation may be di-
rected to:
Technology Utilization Officer 
Manned Spacecraft Center 
Houston, Texas 77058 
Reference: B68-10246
(continued overleaf) 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19680000246 2020-03-12T06:05:18+00:00Z
Patent status: 
No patent action is contemplated by NASA. 
Source: R. R. Walker and C. G. Wickham 
of North American Aviation, Inc. 
under contract to 
Manned Spacecraft Center 
(M SC- l 1869) 
Brief 68-10246 Category 01


Miniature pressure transducer for stressed member application

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server