Mass flowmeter measures rates of flow of all common gases from purges and collected leaks at leak ports. Without dependence on gravity, it measures rates between 5 and 650 cc/min with pressures ranging from 0.001 to 10 to the minus thirteenth torr at temperatures between 70 and 500 degrees K

Morris, T. F.

Wells, F. E.

English

NASA Technical Reports Server

August 1970
	 Brief 70-10050 
NASA TECH BRIEF 
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 Clearinghouse for Federal Scientific and Technical 
Information, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Division, NASA, Code UT, Washington, D.C. 20546. 
Gas Flowmeter 
The problem: 
Development of a mass flowmeter for measurement 
of the rates of flow of all common gases from purges 
and collected leaks at leak ports. Without dependence 
on gravity the meter had to measure rates between 5 
and 650 cm 3 /min (standard) with pressures ranging 
from 1.333 x 10-I to 1.333 x 10- I1 N/rn 2
 (10 to 
10-13 Torr) at ambient temperatures between 70 and 
500K; the gases were to be discharged into a void.
met or exceeded. It handles hydrogen, helium, nitro-
gen, oxygen, organic vapors, and other common gases; 
the principal characteristics are as follows: 
Weight overall	 '-. 3.51 kg or 7.75 lb 
Dimensions, handles and 
inlet included 
Length	 31.7 cm or 12.5 in. 
Width	 ? 3 S	 or 0 ')S in 
The solution:	 Height 
.	 Such a meter has been built and tested successfully Ambient-temperature 
with both nitrogen and helium; all specifications are
	
range
21.6 cm or 8.5 in. 
20 0
 to 500°K 
Configuration of Flowmeter
Max. operating back pres-
sure to ensure 
Thermal insulation 
Metering accuracy 
Orifice pressure at full-
scale flow 
Battery 
Type 
Number of cells 
Voltage, full charge 
Recoverable full-charge 
energy 
Heat sink 
Type 
Temperature range of 
crystallization phase 
change
1.333 x 10-' N/rn 2
 or 
l0 Torr 
1.333 N/rn 2
 or 10-2 Torr 
49.8 x 102
 N/rn 2
 or 
20 in. H20 
Storage, sealed silver-
zinc, rechargeable 
6 
— 7.9 x 10 J or 
22 W-hr 
Uses latent heat of crystal-
lization of Na 2
 HPO4. 
12H20; rechargeable 
306 0
 to 322 0 K or 92 0
 to 120°F
(continued overleaf) 
MW
This document was prepared under the sponsorship of the National
	 Governmtht 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 fràm privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19700000047 2020-03-17T00:03:39+00:00Z
Inlet connection	 0.25 in.; female flare 
(AN) 
Approximate full-scale at 297°K (75°F) [cubic 
centimeters (standard) per minute at 293°K (68°F), 
10.13 x 104 N/rn 2 (760 Torr)I; four gases through 
three orifices.
Orifice 
Gas
1 2 3 
Hydrogen 9500 850 270 
Helium 7000 650 200 
Nitrogen 2500 250 75 
Oxygen 2400 225 70
Note: 
The following documentation may be obtained 
from:
Clearinghouse for Federal Scientific 
and Technical Information 
Springfield, Virginia 22151 
Single document price $3.00 
(or microfiche $0.65) 
Reference: 
NASA-TN-D-5517 (N70-12393), Flow-
meter for space' 
Patent status: 
No patent action is contemplated by NASA. 
Source: T. F. Morris and F. E. Wells 
Marshall Space Flight Center 
(M FS-20663)
. 
Brief 70-10050	 Category 07 


Gas flowmeter

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