Abstract: A method of producing high quality optical surfaces is disclosed. The invention allows for the production of optical surfaces with complex geometry while retaining the high quality of the optical surface. A top layer is provided on a substrate. In order to adhere the top layer to the substrate, an adhesion layer is applied first. In the preferred embodiment, the substrate is an aluminum substrate, the adhesion layer includes a layer of zinc and a layer of nickel and the top layer is gold. The substrate is generally stress free in order to provide a flat surface with no undulations. This allows a relatively thin layer of gold to be applied which then can be diamond turned in order to achieve a reflective layer.

Abstract: An automated tracer system and method for measuring the residence time of wood pulp as it moves through various stages of processing in a pulp mill. A tracer compound comprising a neutral salt of a halogen is introduced into a first location in the path of the pulp slurry; at a second location an automated detector detects the concentration of tracer compound over a time period; a controller relays a voltage signal from the detector to a processor which uses a calibration curve to integrate tracer concentration over time and thereby derive pulp residence, between the first and second locations.

Abstract: An automated system and method for measuring the residence time of wood pulp as it moves through various stages of processing in a pulp mill. A tracer compound comprising a neutral salt of a halogen is introduced into a first location in the path of the pulp slurry; at a second location an automated detector detects the concentration of tracer compound over a time period; a controller relays a voltage signal from the detector to a processor which uses a calibration curve to integrate tracer concentration over time and thereby derive pulp residence, between the first and second locations.