A viscometer, viscosity meter or rheometer is a measuring instrument used to determine a fluid's internal flow resistance or viscosity. The term viscosity typically refers to shear viscosity, i.e., how a material reacts to being sheared. Rotational viscometers with rotating spindles or rotors, also known as "cup and bob" or Searle viscometers, are the most common tools used to measure the shear viscosity of fluids. However, a fluid's viscosity also may be measured on the basis of stretching. The technical term to refer to this is extensional viscosity.A viscometer is frequently used in laboratories, but it also has practical applications in factories and other industrial environments. A viscometer can be an important component in process and quality control. Companies can save money by placing a viscometer in a production line and making fluid viscosity measurements in real time.WAGA offers a variety of handheld, portable, benchtop and in-process, real-time viscometer products that measure the absolute / dynamic (shear) and kinematic viscosity of fluids. Handheld or portable viscosity meter devices allow users to take simple, single-point measurements in the field and in the lab. Benchtop or stationary viscometer devices are complex rheological measuring systems that allow for a more detailed examination of liquid samples.