James E Potzick

44453892, May 1, 1984

Sep 10, 1981

6/300830

James E. Potzick - Potomac MD
Baldwin Robertson - Bethesda MD

The United States of America as represented by the Secretary of Commerce - Washington DC

G01F 166

7386127

A nonintrusive instrument for measuring the volume flowrate of, and the speed of sound in, an arbitrary fluid in a pipe, tube or duct. The sound speed measured is that of a stationary fluid even though the measurement is made while the fluid may be flowing. These measurements are absolute in that they require no flow calibration, and they are independent of the composition of the fluid and its temperature. For a flowing, approximately perfect gas or gas mixture, given the average molecular weight and ratio of specific heats, the instrument measures the temperature. Also, given an independent measurement of the pressure, it measures the gas density and mass flowrate. The measurement can be made in a high noise level environment even when the temperature varies rapidly over a large range. The instrument uses sound whose wavelength is much longer than the diameter of the pipe, tube or duct. As a result, the temperature and flow measurements are independent of the profiles of those quantities across the pipe profiles.

55689930, Oct 29, 1996

Dec 21, 1994

8/360963

James E. Potzick - Potomac MD

The United States of America as represented by the Secretary of Commerce - Washington DC

F16C 1104
F16M 1114

403128

A highly rigid structure is provided using six struts connected at three er and three lower nodes to upper and lower support structures. The joint assemblies are formed by half-spherical balls attached to the ends of each of the struts, and retained within cylindrical apertures, such that the center lines of the struts intersect at the nodes. Bending loads on the struts are thus eliminated, while the design and construction of the structure is substantially simplified.

45203202, May 28, 1985

Feb 22, 1984

6/571288

James E. Potzick - Potomac MD
Baldwin Robertson - Bethesda MD

The United States of America as represented by the Secretary of Commerce - Washington DC

H03K 906
H03K 522
H03K 524

328133

Disclosed is an electronic circuit for determining the phase difference between an input signal and a reference signal where both signals are of the same frequency. Furthermore, the circuit provides an amplitude output indicative of the input signal even when that signal is obscured by noise. A chopper is supplied with the obscured signal input and a reference signal input and provides an output to an integrator which provides a control voltage for a voltage controlled phase shifter which supplies an out of phase input to the chopper. The input to the voltage controlled phase shifter is of the same frequency as the signal obscured by noise. A further output of the voltage controlled phase shifter is 90. degree. out of phase with respect to the reference supplied to the chopper and thus is in phase with the signal obscured by noise and provides the desired marker output. This marker output is also supplied as a reference to a second chopper which is also supplied with the obscured signal as an input.