Viscometers

Viscometers are instruments that measure the viscosity of a fluid, the resistance it offers to flow under an applied force. They fall into two broad working principles: rotational instruments that spin a spindle in the sample and read the torque, and capillary or tube instruments that time how long a fixed volume takes to pass through a calibrated bore. The Questpair catalogue lists new, used and refurbished laboratory viscometers side by side, and of the current listings, 63 percent are used. Prices span a wide field because a simple glass tube and a research rheometer both sit under the same heading. That range is covered in the buying guide below.