Abstract: The invention relates to a device for collecting filtrate samples from a pulp suspension. It comprises a piston rod (3) which, when actuated by a cylinder (2), can reciprocate inside a jacket (5) and which is provided with a filter (4) arranged in an extended position to catch a sample. The filter (4) consists of a wire (6) having a triangular cross-section, the turns (8) of the wire being located close to each other and having their base surface (9) directed outwards and their converging surfaces directed inwards towards the center of the filter (4). During its retracting movement into the jacket the filter (4) is cleaned in the way that fibres which have got stuck on the filter are scraped away by the jacket.

Abstract: The invention relates to a device in viscosity meters for measuring the viscosity of liquid having a large number of contaminants and a low viscosity, the meter including an inner cylinder (5) rotatably mounted in a stationary, outer cylinder (1) in a liquid projecting from a drive unit (12), there being a gap (4) forming a measuring zone between the cylinders (1,5) liquid being propelled through the gap with the aid of a propeller (3) arranged in front of the inner cylinder (5) and in a cavity (10) in the outer cylinder (1). The inner cylinder (5) is provided with an edge (6) projecting out into the gap (4) and the outer cylinder (1) has at least one slot (7) extending in its longitudinal direction and in the flow direction of the liquid, for enabling discharge of the contaminants fastening between the edge (6) and the outer cylinder (1), a self-cleaning strainer system thus being achieved, where the particles in the liquid only negligibly disturb measurement.