Viscometer classification

Capillary viscometers: Capillary viscometers, usually Saylor viscometers, are a common type of viscometer. The working principle is: the sample container (including the outflow capillary) is filled with the sample to be measured in a constant temperature bath, and the liquid column height is h. The cock is opened, the sample begins to flow to the receiver, and the time is calculated until the sample liquid level reaches the scale line. The higher the viscosity of the sample, the longer this period. Therefore, this time directly reflects the viscosity of the sample.
Rotary viscometer: A common rotary viscometer is a cone-plate viscometer. It mainly consists of a flat plate and a conical plate. The motor drives the plate to rotate at a constant speed through the variable speed gear, keeps the tested sample between the two plates by capillary action, and drives the cone plate to rotate by the friction between the molecules of the sample. Under the action of the torsion spring in the torque detector, the cone plate is rotated at a certain Angle and no longer rotates. At this time, the torque applied by the torsion spring is related to the internal molecular friction (i.e., viscosity) of the sample to be measured: the greater the viscosity of the sample, the greater the torque. The torque detector is equipped with a variable capacitor whose moving plate rotates with the cone plate, thereby changing its capacitance value. The torsion spring torque reflected by this capacitance change is the viscosity of the sample to be measured, which is displayed by the instrument.
Vibrating viscometer: The working principle of this viscometer is that the object in the fluid will be hindered by the fluid when it vibrates, and the size of this effect is related to the viscosity of the fluid. Commonly used vibratory viscometers are ultrasonic viscometers with a shrapnel in the detector. When stimulated by pulsed current, the shrapnel produces mechanical vibration in the ultrasonic range. When shrapnel is immersed in the sample under test, the amplitude of the shrapnel is related to the viscosity and density of the sample. If the density is known, the viscosity value can be obtained from the measured amplitude data.