Simplified laser apparatus and method for measuring stock thickness on

Abstract

An apparatus and method for monitoring the de-watering performance of a forming section of a papermaking machine is disclosed which includes a laser instrument having a laser displacement meter laterally spaced and supported above an upper run of a paper forming fabric having a paper stock deposited thereon. A head box deposits paper stock consisting of a water/fiber mixture on top of the upper run. An adjustable C-shaped carrier stand has an upper leg that supports the laser instrument above the upper run of the forming fabric. The carrier stand has a lower leg to support a baseline contact device below the upper run of the forming fabric. The laser displacement meter is disposed at a laser reference position above the forming fabric so that a laser beam is reflected off of the paper stock which is deposited on top of the forming fabric. The baseline device is disposed at a baseline reference position below said forming fabric so that a first distance between the laser reference and the baseline reference can be measured. The laser meter generates a signal representing a second distance of the top surface of the paper stock from the laser referencec. A controller receives the signal and processes an output value indicating the thickness of the paper stock, having the first distance and the thickness of the forming fabric, and hence the water content of the paper stock is monitored.