Instrument for nondestructively measuring compression resistance of spray foam used as thermal insulation was developed. Cylindrical indicator has probe with coil spring to provide force and indicating dial. Probe is manually pressed against area to be tested until complete foot area contacts foam surfaces

Massey, H. S.

Pontious, H. L.

Zinsley, W. M.

English

NASA Technical Reports Server

December 1972
	 B72-10401 
NASA TECH BRIEF 
•	 Marshall Space Flight Center 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Deflection Resistance Indicator 
The problem: 
Spray foam insulation with poor compression resist-
ance has properties which make it unsuitable as thermal 
insulation. Previously, no method existed that would 
determine the quality of spray foam insulation. 
The solution: 
An instrument was developed which measures com-
pression resistance of the spray foam. This test method 
is nondestructive. 
How it's done: 
The indicator, shown in the figure, is a cylindrical 
7.5-cm (3-in) instrument, approximately 15 cm (6 in) 
long, and 5 cm (2 in) in diameter. It has a 7.5-cm 
(3-in) diameter foot, with a 2.5-cm (1-in) diameter probe 
on the bottom. Inside, a coil spring pràvides force 
downward upon the probe. On top, a dial indicator is 
mounted to measure the movement of the probe. 
To operate, the foot of the indicator is placed 
against the area to be tested. The indicator is then 
manually pressed against this area until the complete 7.5-
cm diameter foot area contacts the surface. The dial 
indicator is then read to determine how deep the 2.5-cm 
diameter probe has compressed the test area of the foam. 
Foam with acceptable properties will compress very 
little, while foam which has unsuitable properties will 
compress to a greater extent and give a larger deflection 
reading. 
Note: 
Requests for additional information may be directed 
to:
Technology Utilization Officer 
Marshall Space Flight Center 
Code A&TS-TU 
Huntsville, Alabama 35812 
Reference: B72-10401 
0,
Dial
Indicator
Set 
Screw 
Spring 
Housing
Slide 
Piston 
Patent status: 
No patent action is contemplated by NASA. 
Source: H. L. Pontious, H. S. Massey,

and W. M. Zinsley of

Space Division of
North American Rockwell Corp.

under contract to

Marshall Space Flight Center

(MFS-240 10) 
Category 04 
This document was prepared under the sponsorship of the National
	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States
	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States
	
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19720000400 2020-03-17T03:39:08+00:00Z


Deflection resistance indicator

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