Thickness measurement system and method

A method for measuring the thickness of a flat sheet comprising the steps of:

• (a) at a calculation device, performing a gauge check to determine a first average reading for zero reading sensor data and a second average reading for maximum reading sensor data;
• (b) subtracting said first average reading from said second average reading;
• (c) apply a natural log calculation to the results of step (b);
• (d) determining an incremental length value of said flat sheet;
• (e) sampling measurement values for said flat sheet;
• (f) subtracting said first average reading from said measurement values;
• (g) applying a natural log calculation to the results of step (f);
• (h) subtracting the results of step (f) from the results of step (c);
• (i) applying external compensations and corrections to results of step (h);
• (j) applying an additional linearization calculation involving a polynomial to the results of step (i) to obtain raw thickness values;
• (k) calculating true thickness values as raw thickness values times a product slope factor plus a product offset factor;
• (l) calculating an average value of true thickness values for said incremental length value;
• and
• (m) transferring said average value of true thickness values from said calculation device to a software application at a computer.

A method for measuring the thickness of a flat sheet comprising:

• calculating at a calculation device a plurality of thickness values along the length of said flat sheet based on sensor measurement data;
• correlating each of said thickness measurements with a particular position on said flat sheet;
• transferring said thickness values from said calculation device to a computer;
• and
• displaying data related to said thickness values on an operator display unit at said computer;
• whereby the thickness of said flat sheet at a particular position thereon can be observed.

A method in a computer system for displaying thickness values for a flat sheet comprising the steps of:

• displaying on a vertical axis a plurality of thickness values within a range of numbers;
• displaying on horizontal axis a plurality of numbers relating to positions on said flat sheet;
• and
• for each position on said flat sheet, displaying an indicator representing a calculated thickness value corresponding to said position on said flat sheet.

A system for measuring the thickness of a flat sheet comprising:

• a source/detector unit for collecting sensor measurement data;
• a calculation device for calculating thickness values for said flat sheet based on said sensor measurement data from said source/detector unit;
• a computer for receiving thickness values from said device;
• an operator display unit at said computer for displaying said thickness values;
• and
• a process control system for receiving error signal output from said calculation device;
• wherein said error signal output is selected from the group consisting of actual, average, and exponentially filtered values representing the error values of calculated thicknesses and a target thickness.

A system for measuring the thickness of a flat sheet comprising:

• a source/detector unit for collecting sensor measurement data;
• a calculation device for calculating thickness values for said flat sheet based on said sensor measurement data from said source/detector unit;
• a computer for receiving thickness values from said device;
• an operator display unit at said computer for displaying said thickness values;
• and
• a deviation meter adapted to display a thickness value as a deviation from a specified target thickness value.

A method for measuring the thickness of a flat sheet comprising:

• calculating at a calculation device thickness values for said flat sheet based on sensor measurement data;
• transferring said thickness values from said calculation device to a computer;
• displaying data related to said thickness values on an operator display unit at said computer;
• and
• transmitting to a process control system error signal output based on said thickness values;
• wherein said error signal output is selected from the group consisting of actual, average, and exponentially filtered values representing the error values of calculated thicknesses and a target thickness.

A method for measuring the thickness of a flat sheet comprising:

• calculating at a calculation device thickness values for said flat sheet based on sensor measurement data;
• transferring said thickness values from said calculation device to a computer;
• displaying data related to said thickness values on an operator display unit at said computer;
• and
• comparing at said calculation device said thickness values to a target thickness value and transmitting a signal to a production device if thickness values are outside specified limits for said target thickness value.