Richard D Kent

US Patent:

7596988, Oct 6, 2009

Filed:

Mar 2, 2005

Appl. No.:

10/598071

Inventors:

James E. Usowicz - Webster MA, US
Peyton C. Beals - Wrentham MA, US
Russell Keene - Sudbury MA, US
Richard Kent - Norfolk MA, US
Miguel Soares - Norton MA, US
John Heden - Hollis NH, US

Assignee:

Waters Technologies Corporation - Milford MA

International Classification:

G01N 30/28
G01N 30/32

US Classification:

73 6152, 73 6155, 73 6156, 73 6157, 210635, 422 70

Abstract:

A device () for detecting a condition in a fluid system () and initiating a response based on the condition. The device consists of a sensor () that responds to a first and second condition of the fluid () in the system and a control means () that receives the responses and generates command signals in based on the received response. In a liquid chromatography system, the device is used to determine the volume of components of the fluid system. In addition, the device allow leaks to be detected and permits the fluid in the system to be transported at a optimum speed. The device is well implemented utilizing to a light emitter and light receptor that are sensitive to the fluid in either a gaseous or liquid state.

US Patent:

7607823, Oct 27, 2009

Filed:

Mar 2, 2005

Appl. No.:

10/597857

Inventors:

Richard Kent - Norfolk MA, US

Assignee:

Waters Technologies Corporation - Milford MA

International Classification:

G01N 27/20
G01K 1/00
G01K 7/22

US Classification:

374 4, 374 43, 374 45, 374147, 374185, 374163

Abstract:

A system and method for detecting leaks includes a sensing circuit including a first thermistor device adapted to detected a leak upon contact with a liquid, and, a second thermistor device functioning as a reference device. The first and second thermistor devices are driven with a current such that both devices operate in self-heated mode at a temperature above an ambient temperature. A control system controls a drive circuit for maintaining a constant application of power through both devices in response to a voltage monitored at a reference point in the sensing circuit including the reference thermistor. The voltage at a reference point in a portion of the sensing circuit including the first thermistor device is additionally monitored and compared with the voltage at the reference point in the sensing circuit including the second thermistor device. A leak condition is determined on the basis of a comparison result of the ambient temperature.