Apparatus for measuring paper stock consistency

A densitometer for paper stock has a wide, vertical metal pipe with a central inlet. Two restricted nozzles in the pipe are equidistant from the inlet in opposite vertical directions and connected to the two leg ends of an inverted U-tube by narrow copper tubes soldered to the outside of the wide tube and to each other for heat transfer. A pump drives the measured stock through the inlet and from both ends of the pipe through a common outlet restricted to maintain high pressure in the system. The copper tubing is supplied with respective streams of the liquid in the stock at a very slow rate by means of a second pump and a filter which removes the fibers from the pumped liquid.