Harold F Hemond

US Patent:

20100198547, Aug 5, 2010

Filed:

Nov 3, 2009

Appl. No.:

12/611454

Inventors:

Ann E. Mulligan - East Falmouth MA, US
Alan T. Gardner - E. Falmouth MA, US
Terence Hammar - East Falmouth MA, US
Charles Harvey - Concord MA, US
Harold F. Hemond - Lexington MA, US

Assignee:

WOODS HOLE OCEANOGRAPHIC INSTITUTION - Woods Hole MA

International Classification:

G01F 1/34
G06F 19/00

US Classification:

702100, 7386142

Abstract:

The systems and methods described herein related to measuring hydraulic parameters across a surface water-aquifer interface. In particular, the systems include a pressure differential sensor within a watertight housing. The pressure differential sensor has two inlets, one of which is connected to a piezometer located in an aquifer, and the other of which is connected to a surface water body. A solenoid valve allows the systems to switch between a first, measurement configuration and a second, calibration configuration. A pump and a conductivity-temperature sensor enable a third and fourth configuration for measuring the electrical conductivity and temperature of surface water and groundwater. The collected data is then locally stored or transmitted wirelessly. The low-power components and calibration capabilities of the systems allow for long-term deployment, on the order of six months or more.

US Patent:

20120205534, Aug 16, 2012

Filed:

Feb 14, 2012

Appl. No.:

13/396321

Inventors:

Ian W. Hunter - Lincoln MA, US
Brian D. Hemond - Cambridge MA, US
Harold F. Hemond - Lexington MA, US

International Classification:

H01J 49/24
H01J 49/26

US Classification:

250282, 250281

Abstract:

A miniature, low cost mass spectrometer capable of unit resolution over a mass range of 10 to 50 AMU. The mass spectrometer incorporates several features that enhance the performance of the design over comparable instruments. An efficient ion source enables relatively low power consumption without sacrificing measurement resolution. Variable geometry mechanical filters allow for variable resolution. An onboard ion pump removes the need for an external pumping source. A magnet and magnetic yoke produce magnetic field regions with different flux densities to run the ion pump and a magnetic sector mass analyzer. An onboard digital controller and power conversion circuit inside the vacuum chamber allows a large degree of flexibility over the operation of the mass spectrometer while eliminating the need for high-voltage electrical feedthroughs. The miniature mass spectrometer senses fractions of a percentage of inlet gas and returns mass spectra data to a computer.

US Patent:

51553570, Oct 13, 1992

Filed:

Jul 23, 1990

Appl. No.:

7/556751

Inventors:

Harold F. Hemond - Lexington MA

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

B01D 5944
H01J 4900

US Classification:

250291

Abstract:

A portable mass spectrometer system. The system includes a sample inlet for receiving a sample of analyte molecules and an ion source for producing sample ions by ionization of the sample molecules. A cycloid mass analyzer is provided and adapted to receive the sample ions. The mass analyzer has a means for inducing an electric field in an analysis region and a rear earth permanent magnet material for inducing a static magnetic field in the analysis region, oriented substantially normal to the electric field. A detector is provided for detection of said sample ions in the analysis region. A vacuum means maintains a low pressure in the analysis region. In various embodiments, the system is hand-portable and self-contained, including a 12V rechargeable battery power supply, and a magnet that includes a rare earth permanent magnetic material such as neodymium-iron and samarium-cobalt alloys.

US Patent:

44634544, Jul 31, 1984

Filed:

May 5, 1981

Appl. No.:

6/260564

Inventors:

Harold C. Hemond - Ledyard CT
William H. Ezell - New London CT

Assignee:

Rockwell International Corporation - El Segundo CA

International Classification:

H04R 1700

US Classification:

367173

Abstract:

An apparatus for supporting in a housing, a mount adapted to carry a transducer, the mount having a predetermined positional locus, the apparatus comprising: cooperating sets of magnets attached to the mount and the housing, respectively the sets of magnets acting to positionally bias the mount toward an equilibrium position within the predetermined locus and freely of housing vibration transmittal to the mount.

US Patent:

20200388479, Dec 10, 2020

Filed:

May 18, 2020

Appl. No.:

16/876527

Inventors:

- Cambridge MA, US
Brian D. Hemond - Cambridge MA, US
Harold F. Hemond - Lexington MA, US

International Classification:

H01J 49/30
H01J 49/00
H01J 49/14
H01J 49/02
H01J 49/24

Abstract:

A miniature, low cost mass spectrometer capable of unit resolution over a mass range of 10 to 50 AMU. The mass spectrometer incorporates several features that enhance the performance of the design over comparable instruments. An efficient ion source enables relatively low power consumption without sacrificing measurement resolution. Variable geometry mechanical filters allow for variable resolution. An onboard ion pump removes the need for an external pumping source. A magnet and magnetic yoke produce magnetic field regions with different flux densities to run the ion pump and a magnetic sector mass analyzer. An onboard digital controller and power conversion circuit inside the vacuum chamber allows a large degree of flexibility over the operation of the mass spectrometer while eliminating the need for high-voltage electrical feedthroughs. The miniature mass spectrometer senses fractions of a percentage of inlet gas and returns mass spectra data to a computer.

US Patent:

20190214243, Jul 11, 2019

Filed:

Mar 13, 2019

Appl. No.:

16/351700

Inventors:

- Cambridge MA, US
Brian D. HEMOND - Cambridge MA, US
Harold F. HEMOND - Lexington MA, US

International Classification:

H01J 49/30
H01J 49/02
H01J 49/24
H01J 49/00
H01J 49/14

Abstract:

A miniature, low cost mass spectrometer capable of unit resolution over a mass range of 10 to 50 AMU. The mass spectrometer incorporates several features that enhance the performance of the design over comparable instruments. An efficient ion source enables relatively low power consumption without sacrificing measurement resolution. Variable geometry mechanical filters allow for variable resolution. An onboard ion pump removes the need for an external pumping source. A magnet and magnetic yoke produce magnetic field regions with different flux densities to run the ion pump and a magnetic sector mass analyzer. An onboard digital controller and power conversion circuit inside the vacuum chamber allows a large degree of flexibility over the operation of the mass spectrometer while eliminating the need for high-voltage electrical feedthroughs. The miniature mass spectrometer senses fractions of a percentage of inlet gas and returns mass spectra data to a computer.

US Patent:

20170316928, Nov 2, 2017

Filed:

Jul 10, 2017

Appl. No.:

15/645147

Inventors:

Ian W. HUNTER - Lincoln MA, US
Brian D. HEMOND - Cambridge MA, US
Harold F. HEMOND - Lexington MA, US

International Classification:

H01J 49/30
H01J 49/02
H01J 49/00
H01J 49/00
H01J 49/24
H01J 49/14

Abstract:

A miniature, low cost mass spectrometer capable of unit resolution over a mass range of 10 to 50 AMU. The mass spectrometer incorporates several features that enhance the performance of the design over comparable instruments. An efficient ion source enables relatively low power consumption without sacrificing measurement resolution. Variable geometry mechanical filters allow for variable resolution. An onboard ion pump removes the need for an external pumping source. A magnet and magnetic yoke produce magnetic field regions with different flux densities to run the ion pump and a magnetic sector mass analyzer. An onboard digital controller and power conversion circuit inside the vacuum chamber allows a large degree of flexibility over the operation of the mass spectrometer while eliminating the need for high-voltage electrical feedthroughs. The miniature mass spectrometer senses fractions of a percentage of inlet gas and returns mass spectra data to a computer.

US Patent:

20160172180, Jun 16, 2016

Filed:

Feb 17, 2016

Appl. No.:

15/045883

Inventors:

- Cambridge MA, US
Brian Hemond - Cambridge MA, US
Harold F. Hemond - Lexington MA, US

International Classification:

H01J 49/30
H01J 49/02
H01J 49/24
H01J 49/00
H01J 49/14

Abstract:

A miniature, low cost mass spectrometer capable of unit resolution over a mass range of 10 to 50 AMU. The mass spectrometer incorporates several features that enhance the performance of the design over comparable instruments. An efficient ion source enables relatively low power consumption without sacrificing measurement resolution. Variable geometry mechanical filters allow for variable resolution. An onboard ion pump removes the need for an external pumping source. A magnet and magnetic yoke produce magnetic field regions with different flux densities to run the ion pump and a magnetic sector mass analyzer. An onboard digital controller and power conversion circuit inside the vacuum chamber allows a large degree of flexibility over the operation of the mass spectrometer while eliminating the need for high-voltage electrical feedthroughs. The miniature mass spectrometer senses fractions of a percentage of inlet gas and returns mass spectra data to a computer.