What is claimed is:
1. A turbine bucket having a bucket airfoil shape in an envelope within 0.160 inches in a direction normal to any airfoil surface location wherein the airfoil has an uncoated nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in inches in Table I wherein Z is a perpendicular distance from a plane normal to a radius of the turbine centerline and containing the X and Y values with the Z value commencing at zero in the X, Y plane at a radially innermost aerodynamic section of the airfoil and X and Y are coordinate values defining the airfoil profile at each distance Z, the profiles at the Z distances being joined smoothly with one another to form the complete airfoil shape.
2. A turbine bucket according to claim 1 forming part of a fourth stage of a turbine.
3. A turbine bucket having an uncoated nominal airfoil profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in inches in Table I wherein Z is a perpendicular distance from a plane normal to a radius of the turbine centerline and containing the X and Y values with the Z value commencing at zero in the X, Y plane at a radially innermost aerodynamic section of the airfoil and X and Y are coordinate values defining the airfoil profile at each distance Z, the profiles at the Z distances being joined smoothly with one another to form the complete airfoil bucket profile; the X, Y and Z values being scaled as a function of the same constant or number to provide a scaled-up or scaled-down bucket airfoil.
4. A turbine bucket according to claim 3 forming part of a fourth stage of a turbine.
5. A turbine comprising a turbine wheel having a plurality of buckets, each of said buckets having an airfoil shape in an envelope within 0.160 inches in a direction normal to any bucket airfoil surface location wherein the airfoil has an uncoated nominal profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in inches in Table I wherein Z is a perpendicular distance from a plane normal to a radius of the turbine centerline and containing the X and Y values with the Z value commencing at zero in the X, Y plane at a radially innermost aerodynamic section of the airfoil and X and Y are coordinate values defining the airfoil profile at each distance Z, the profiles at the Z distances being joined smoothly with one another to form the complete airfoil shape.
6. A turbine according to claim 5 wherein the turbine wheel comprises the fourth stage of the turbine.
7. A turbine according to claim 5 wherein the turbine wheel has eighty-eight buckets and the Y direction represents a distance parallel to a rotary axis of the turbine wheel.
8. A turbine comprising a turbine wheel having a plurality of buckets, each of said buckets having an uncoated nominal airfoil profile substantially in accordance with Cartesian coordinate values of X, Y and Z set forth in inches in Table I wherein Z is a perpendicular distance from a plane normal to a radius of the turbine centerline and containing the X and Y values with the Z value commencing at zero in an X, Y plane at the radially innermost aerodynamic section of the airfoil and X and Y are coordinate values defining the airfoil profile at each distance Z, the profiles at the Z distances being joined smoothly with one another to form the complete airfoil shape;
the X, Y and Z values being scaled as a function of the same constant or number to provide a scaled-up or scaled-down bucket airfoil.
9. A turbine according to claim 8 wherein the turbine wheel comprises the fourth stage of the turbine.
10. A turbine according to claim 8 wherein the turbine wheel has eighty-eight buckets and the Y direction represents a distance parallel to a rotary axis of the turbine wheel.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. An optical spectrum monitoring system, comprising:
a tunable filter that filters an optical signal;
a signal detector that detects a filtered optical signal from the tunable filter;
a logarithmic amplifier that amplifies the output of the signal detector;
an analog to digital converter for converting the output of the logarithmic amplifier spectrum into sample data; and
a data processing subsystem that analyzes the sample data.
2. An optical spectrum monitoring system as claimed in claim 1, further comprising:
a package;
an optical bench installed within the package, the tunable filter and the detector being connected to optical bench;
a temperature detector for detecting a temperature within the package; and
a thermoelectric cooler for controlling a temperature of the package.
3. An optical spectrum monitoring system as claimed in claim 2, wherein the log amplifier is installed within the package.
4. An optical spectrum monitoring system as claimed in claim 2, wherein the logarithmic amplifier is installed on the optical bench.
5. An optical spectrum monitoring system as claimed in claim 1, wherein the tunable filter is a microelectromechanical tunable filter.
6. An optical spectrum monitoring system as claimed in claim 1, wherein the tunable filter has a Lorentzian pass band and the data processing subsystem deconvolves the Lorentzian pass band from the sample data.
7. An optical spectrum monitoring system as claimed in claim 1, wherein the data processing subsystem detects peaks in the spectrum using the sample data and uploads peak information to a host computer before performing processing to determine the shape of the peaks andor noise information for the optical signal.
8. An optical spectrum monitoring system as claimed in claim 1, wherein the data processing subsystem detect spectral locations of the peaks in a spectrum.
9. An optical spectrum monitoring system as claimed in claim 1, wherein the data processing subsystem uploads the sample data to a host computer before uploading peak information to the host computer.
10. An optical spectrum monitoring system as claimed in claim 1, wherein the data processing subsystem begins detecting the peaks before completion of the conversion of the spectrum into the sample data.
11. A method for capturing spectrum information in an optical spectrum monitoring system, the method comprising:
filtering an optical signal;
detecting a filtered optical signal;
logarithmically amplifying the detected signal;
an analog to digitally converting the logarithmically amplified signal to generate sample data.
12. A method as claimed in claim 11, further comprising calibrating the sample data in response to calibration information.
13. A method as claimed in claim 11, further comprising uploading the sample data to the host computer before uploading peak information to the host computer.
14. A method as claimed in claim 11, further comprising beginning the step of detecting the spectral locations of peaks before completion of the step of converting the logarithmically amplified signal into the sample data.