Nip pressure sensing system

A method for determining characteristics of a first roll configured with a second roll in a nip press including measuring nip widths between the rolls while the rolls are in a static condition, said method comprising the steps of:

• providing a strip having a fiber optic sensor for providing signals representative of nip width between said first and second rolls, the sensor having an effective sensing length greater than the expected nip width and being configured such that, when the sensor is stationarily positioned between the two nip rolls with at least a portion of the sensor positioned within the nip width, the sensor is operative to respond to pressure exerted thereon by the two nip rolls by providing a signal proportional to the area of the sensor under pressure;
• placing and maintaining the strip between the two nip rolls with at least a portion of the sensor positioned within the nip width and such that the effective sensing length extends entirely across the nip width;
• while the sensor is stationarily positioned with respect to the nip width and the effective sensing length extends entirely across the nip width, generating signals with the sensor which are proportional to the area of the sensor under pressure;
• and
• computing measurements from said signals with a computer in communication with said sensor.