Lightweight, portable device has been developed to permit probe movement in two planes. It also provides accurate information about location of probe tip in a closed chamber

Perkins, C. W.

English

NASA Technical Reports Server

February 1973	 B73-10034 
•	
NASA TECH BRIEF 
NASA Pasadena Office 
--
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. 
Mechanical Positioning Device for Langmuir Probe 
The Langmuir probe is frequently used to measure 
the properties of plasmas. For simple systems, a probe 
fixed in one position is adequate, but when plasmas in 
large-volume systems are to be studied, it is quite 
desirable to have a movable probe. In the past, posi-
tioning systems have been limited to movement in 
one plane, and a different probe and positioning de-
vice has been used to measure properties in another 
plane. Unfortunately, substitution of one system for 
another has led to difficulties in the correlation of 
•
data from the separate systems. 
A mechanical positioning device for a Langmuir 
probe has been developed to permit probe movement 
in two planes; it also provides accurate information 
as to the location of the probe tip in a closed chamber. 
The device consists primarily of a probe carriage 
unit which is moved forward or backward inside a 
rectangular frame by a motor-driven lead screw. The 
carriage unit supports one end of the Langmuir probe 
in a retainer socket centered upon a gear and the 
other, end slides in a slot in the frame which acts as a 
guide for the carriage unit. The lead screw has a 
worm gear at one end which drives a rotary potenti-
ometer; with appropriate readout instrumentation, 
accurate information as to the axial position of the 
probe tip can be obtained. The retainer-socket gear
is driven by a motor to rotate the probe (when it has 
an offset termination) and accurate information on 
the radial position of the probe is provided by a 
potentiometer that is coupled to the retainer socket 
drive. 
The unit is lightweight and portable; it can also be 
used to position probes in nozzles, ducts, and other 
chambers for measurements of flow and temperature. 
Note: 
Requests for further information may be directed 
to:
Technology Utilization Officer 
NASA Pasadena Office 
4800 Oak Grove Drive 
Pasadena, California 91103 
Reference: TSP 73-10034 
Patent status: 
NASA has decided not to apply for a patent. 
Source: Cecil W. Perkins of

Caltech/JPL
under contract to

NASA Pasadena Office

(NPO-11626) 
Category 06 
	
Whis 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=19730000034 2020-03-17T06:36:30+00:00Z


Mechanical positioning device for Langmuir probe

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server