Abstract: A system for monitoring corrosion in metal by comparing a test sample exposed to a corrosion causing environment and a reference sample exposed to a protected environment. An AC voltage source generates a square wave signal oscillating between ground and voltage Vcc and a filter is positioned to filter the signal to produce a sine wave with no second harmonic component. A voltage-driven current source and inverting amplifier produce a current referenced to 0.5 Vcc to provide an AC current from the drive voltage driven sinusoidally and symmetrically above and below 0.5 Vcc. A transformer steps up the AC current and thereafter transmits the current through the samples to an amplifier for amplifying the current to provide outputs in a ratio representing the degree of corrosion of the reference sample. The system can operate in situ for on site measurement and uses relatively low current to permit long operation.

Abstract: An apparatus and method for finishing a tubular fabric where the apparatus includes a fabric spreader for spreading the tubular fabric into a flattened tube. Edge drive means are provided to move the tube of fabric over a spreader past a fabric treating station. Control means are provided for maintaining and controlling a cross-line configuration of the fabric and/or width of the fabric. The control means comprises a pair of spaced opposed control rolls rotatable in opposite directions with the fabric passing over substantial arcs of each of the rolls. Speed control means are included for varying the speed of the control rolls with respect to the edge drive means to tension or bunch the fabric with respect to edge portions of the fabric driven by the edge drive means.