Welcome to Qinsun Instruments Co., Limited.
2023-07-04 0 Views

Principle of the rotational viscometer

The rotational viscometer is used to measure the viscous resistance and dynamic liquid viscosity of liquids, and is widely used to measure the viscosity of various liquids, such as oil, paint, plastic, food, medicine, cosmetics, adhesive products, etc. etc. 2p1Textile Testing Instruments, Testing Equipment Manufacturer


Working principle of the rotary viscometer: 2p1Textile Testing Instruments, Testing Equipment Manufacturer


1. Working principle: 2p1Textile Testing Instruments, Testing Equipment Manufacturer


When measuring, the inner cylinder is Simultaneous with the outer cylinder submerged in the drilling fluid, they are concentric cylinders with an annular gap of 1.17mm. As the outer cylinder rotates at constant speed, it drives the drilling fluid in the annulus to rotate. 2p1Textile Testing Instruments, Testing Equipment Manufacturer


Due to the viscosity of the drilling fluid, the inner cylinder connected to the torsion spring rotates at an angle. According to Newton's law of internal friction, the magnitude of the angle of rotation is proportional to the viscosity of the drilling fluid, so themeasuring the viscosity of the drilling fluid is converted into measuring the angle of rotation of the inner cylinder. 2p1Textile Testing Instruments, Testing Equipment Manufacturer


The size of the rotation angle can be read directly from the dial, which is why this viscometer is also called a direct-read rotation viscometer. 2p1Textile Testing Instruments, Testing Equipment Manufacturer


2. Measuring principle: 2p1Textile Testing Instruments, Testing Equipment Manufacturer


①Relationship between shear rate and rotation speed: 1 rpm (generally expressed as rpm) = 1.703 s-1 ; 2p1Textile Testing Instruments, Testing Equipment Manufacturer


②The indicator q (q is degree on circumference, unit can be omitted) is proportional to shear stress t (unit is Pa). If the designed torsional spring coefficient is 3.87?10-5, the relationship between the two can be expressed as follows: t = 0.511 q (Pa). 2p1Textile Testing Instruments, Testing Equipment Manufacturer

2p1Textile Testing Instruments, Testing Equipment Manufacturer