Fast, accurate, multipressure measuring system, which employs a multiple port pressure scanning valve that connects a pressure transducer to many pressures, is described

Vincent, E. R.

English

NASA Technical Reports Server

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September 1964	 Brief 64-10031 
NASA TECH BRIEF 
This NASA Tech Brief is issued by the Technology Utilization Division to acquaint 
industry with the technical content of an innovation derived from the space program. 
Multiple Port Pressure Scanner Valve Features Greater Accuracy,
Quicker Data
Slip Ring
FIGURE 2 
.
The problem: Fast, accurate measurement of many 
pressures and quick reduction of the recorded data. 
The solution: A multiple port pressure scanning 
valve that successively connects a pressure transducer 
to many pressures and gives a quick readout for rapid 
data reduction. 
How it's done: A multipressure measuring system 
is designed around an electronic manometer with a 
range of zero to 300 centimeters of mercury absolute, 
and an accuracy of ±0.005 mm of mercury measured 
at 0.20 mm of mercury. 
A stationary cylindrical pressure port block is fitted 
with multiple ports around its periphery. Four of these 
ports are connected to "standards" for random leak 
checking; a fifth is connected to a hard vacuum source 
used for system checking, and the balance are avail-
able for measuring pressures within the range of the
transducer. The port block has axially bored passages 
intersecting each of the ports and opening on the face 
of the port block. A stationary disc, immediately 
above the port block, is punched and fitted with 0-ring 
seals that index with the passages. A rotor mounting 
a pressure transducer is attached to a hollow shaft in 
a plane immediately above the stationary disc. The 
transducer is electrically connected by a cable feeding 
down through the bore of the shaft. A drive disc is 
attached to the shaft and includes a set of cam 
followers around the periphery of its underside. The 
cam followers are engaged by the worm-type gear of a 
drive mechanism mounted at right angles. 
An insulator ring with two . pairs of wipers is 
mounted to the underside of the drive disc. As the 
assembly revolves, the wipers contact a stationary 
commutator—part of a port indicator system. Cables 
(continued overleaf) 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States Govern-
ment. nor NASA, nor any person acting on behalf of NASA: A. Makes 
any warranty or representation, express or implied, with respect to the 
accuracy, completeness, or usefulness of the information contained in
this document, or that the use of any information, apparatus, method, 
or process disclosed in this document may not infringe privately-owned 
rights: or B. Assumes any liabilities with respect to the use of, or for 
damages resulting from the use of, any information, apparatus, method. 
or process disclosed in this-document.
https://ntrs.nasa.gov/search.jsp?R=19640000017 2020-03-11T17:06:48+00:00Z
lead to an external array of indicator lights that show 
which of the ports is being sampled. 
The lower end of the hollow shaft mounts a slip 
ring assembly that is in contact internally with a 
set of transducer lead wipers and externally with a set 
of wipers connected to a readout cable. As the re-
volving members rotate, the transducer samples each 
connected pressure in turn, and the readout may be 
used in any manner the user prefers. The output of the 
subject model is used to record 99 channels of pressure 
data on punched paper tape in about 30 seconds. The 
tape is then used as input to a computer for final data 
reduction. The time used for data acquisition, tabula-
tion, and reduction is thus reduced from, several days 
to a matter of minutes. Additionally, systematic and 
random errors of previous methods are eliminated. 
Leak testing and efficiency checking of the multi-
port valve is quickly accomplished using a monitor 
port in a pressure dome in conjunction with readings 
from the four ports connected to "standards" and the 
one connected to a hard vacuum. A comparison of the 
hard vacuum reading and a "standard" reading with 
dome pressure reveals any leaks.
Notes: 
This device could be used to monitor pressure drop 
and flow rates in large industrial filter installations. 
2. Numerous critical pressure points in chemical or 
pharmaceutical processing plants could be moni-
tored at a central point and continuous records 
maintained. 
3. Inquiries concerning this invention may be directed 
to:
Technology Utilization Officer 
Jet Propulsion Laboratory 
4800 Oak Grove Drive 
Pasadena, California, 91103 
Reference: B64-10031 
Patent status: NASA encourages the immediate 
commercial use of this invention. It is owned by 
NASA and inquiries about obtaining royalty-free 
rights for its commercial use may be made to NASA 
Headquarters, Washington, D.C., 20546. 
Source: Earl R. Vincent 
(J PL-555) 
Brief 64-10031


Multiple port pressure scanner valve features greater accuracy, quicker data

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