US4761552A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Standard for near-infrared reflectance measurement and method of making the same
Assignee: Zeltex Inc
•
Filing: 1986-09-16
•
Granted: 1988-08-02
•
Expires: 2006-09-16
Abstract
Abstract A fixed stable standard for near-infrared reflectance measurement is provided by using a sample holder having an IR-quartz window and a measured amount of PTFE powder pressed directly thereagainst so that the PTFE powder has a fixed density providing a permanent reflectance standard protected by the window, and a method of making the standard is also provided.
Inventors
- 👤 Robert D. Rosenthal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:20
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/47; G01N21/4785; G01N21/25; G01N21/31; G01N21/35; G01N21/3563; G01N21/359
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
104 words
In combination with an analyzer for quantitative measurements for at least one constituent of interest in a sample by optical measurements, a calibration standard comprising, a calibration standared holder having a cup-shaped cavity closed at one end by an IR-quartz window, a pressed PTFE layer of a predetermined density and thickness in the cavity pressed onto and adjacent the IR-quartz window and having an upper surface substantially parallel to the surface against the IR-quartz window, and a sealing member in the cavity premanently sealing the pressed PTFE layer, the member being of a material which does not affect the optical characteristics of the standard.
Claim 2
Dependent Claim
104 words
In combination with an analyzer for quantitative measurements for at least one constituent of interest in a sample by optical measurements, a calibration standard comprising, a calibration standared holder having a cup-shaped cavity closed at one end by an IR-quartz window, a pressed PTFE layer of a predetermined density and thickness in the cavity pressed onto and adjacent the IR-quartz window and having an upper surface substantially parallel to the surface against the IR-quartz window, and a sealing member in the cavity premanently sealing the pressed PTFE layer, the member being of a material which does not affect the optical characteristics of the standard.
Claim 3
Independent Claim
82 words
A method of making a reflectance standard for use with optical measuring instruments, the standard being pressed powdered PTFE, the method comprising; placing a predetermined quantity of PTFE within a cavity and adjacent an IR-quartz window in the cavity, compressing the predetermined quantity of powdered PTFE with a piston in the cavity and positively limiting the movement of the piston to compress the powdered PTFE so as to produce the desired density powdered PTFE while also providing a relatively rugged non-fragile standard.
Claim 4
Independent Claim
82 words
A method of making a reflectance standard for use with optical measuring instruments, the standard being pressed powdered PTFE, the method comprising; placing a predetermined quantity of PTFE within a cavity and adjacent an IR-quartz window in the cavity, compressing the predetermined quantity of powdered PTFE with a piston in the cavity and positively limiting the movement of the piston to compress the powdered PTFE so as to produce the desired density powdered PTFE while also providing a relatively rugged non-fragile standard.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-02 | 1992-02-01 | 1992-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-02 | 1996-02-01 | 1996-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-02 | 2000-02-01 | 2000-08-02 | $7700.00 | Window Closed / Lapsed |