Paper property sensing system

A sensor system for measuring physical properties of a sheet, the sensor system comprising:

• a) a first member and a second member positioned in opposition to each other to each respectively contact the sheet passing therebetween;
• b) a first base coupled to the first member, the first member extending from the first base at a predefined first angle;
• c) a second base coupled to the second member;
• d) a first measurement unit coupled to the first member for measuring the displacement of the first member by measuring a differential change in the predefined first angle as the sheet passes between the first and second members, the first measurement unit including a strain gauge coupled to the first member to measure a flexure of the first member;
• and
• e) a second measurement unit coupled to the second member for measuring displacement of the second member as the sheet passes between the first and second members, the second measurement unit measuring the displacement of the first member by measuring a differential change in the predefined angle as the sheet passes between the first and second members, the first measurement unit including a strain gauge coupled to the second member to measure a flexure of the second member.

A sheet handling machine comprising:

• a) a sheet transport mechanism for moving a sheet in response to a control signal;
• b) a controller coupled to the sheet transport mechanism for generating the control signal in response to a first property signal;
• and
• c) a sensor system coupled to the sheet transport mechanism and generating the first property signal, the sensor system including:
• 1) a first member and a second member positioned in opposition to each other to each respectively contact the sheet passing therebetween;
• 2) a first base coupled to the first member;
• 3) a second base coupled to the second member;
• 4) a first measurement unit coupled to the first base for measuring displacement of the first member relative to the first base as the sheet passes between the first and second members;
• and
• 5) a second measurement unit coupled to the second base for measuring displacement of the second member relative to the second base as the sheet passes between the first and second members.