Viscosity Meter Comprehensive Analysis: Principles, Usage Methods, Common Faults, and Repair Methods for Enhanced Measurement Accuracy

Overview of Viscosity Meters

A viscosity meter (Viscosimeter) is an instrumental device used for the physical analysis of fluid (liquid and gas) viscosity. Viscosity, a physical quantity representing internal friction during fluid flow, reflects the fluid’s resistance to deformation and serves as a crucial indicator for assessing the quality of certain finished or semi-finished products. Varying with fluid type and temperature, viscosity finds wide application in fields such as petroleum, chemicals, electric power, metallurgy, and national defense.

Principles

Viscosity meters are primarily categorized into three types based on operation mode: capillary, rotational, and vibrational.

• Capillary Viscosity Meters: The common example is the Saybolt viscometer, which works by measuring the time taken for a sample to flow through a capillary tube to determine its viscosity. The sample container, filled with the test sample and placed in a constant temperature bath, indicates higher viscosity when the sample takes longer to flow through the capillary.
• Rotational Viscosity Meters: One of the most commonly used in laboratories is the cone-and-plate viscometer. It operates through an electric motor driving a plate to rotate at a constant speed, maintaining the sample between two plates via capillary action. The friction between sample molecules drives the cone’s rotation, and the torque detected by a torsion spring reflects the sample’s viscosity after the cone rotates a certain angle.
• Vibrational Viscosity Meters: Examples include ultrasonic viscometers, which emit vibrations of a specific frequency through a vibration sensor. By measuring changes in vibration amplitude or the driving force required to maintain consistent amplitude, the viscosity is calculated. When the vibrating element is immersed in the test sample, its amplitude correlates with the sample’s viscosity and density.

Usage Methods

• Ensure the instrument is level.
• Avoid bubbles when inserting the rotor into the sample; tilt insertion followed by straightening ensures the rotor does not touch the container walls or bottom, and the sample exceeds the prescribed mark.
• Keep the rotor clean and dry before measuring different samples to prevent residue from affecting accuracy.
• Pay special attention to the temperature of the liquid being measured, ideally maintaining it at a specified temperature point with a precision of no more than 0.1℃ deviation.
• Select the appropriate rotor and speed based on the sample’s viscosity, adjusting the speed to keep readings within a reasonable range.
• Connect the rotor correctly, supporting the spindle with the left hand while rotating the rotor with the right to protect internal components.
• Regularly calibrate the instrument using viscosity standard liquids to ensure measurement accuracy.

Faults and Repair Methods

• Inaccurate Readings:
  • Check the power supply for stability and damage.
  • Calibrate the instrument using standard liquids.
  • Clean the sensor and ensure secure connections.
  • Confirm the suitability, uniformity, and sufficiency of the sample.
• Rotor Failure to Rotate:
  • Inspect the rotor and bearing for damage or lubrication needs.
  • Check the circuit board and connections for damage or poor contact.
• Display Issues:
  • Verify the display’s functionality and proper connection.
  • Ensure the control software is up to date.
• Data Transmission Problems:
  • Confirm correct and compatible data cable connections.

Maintenance Plan

• Regularly clean the rotor and viscometer after measurements to avoid residue.
• Establish a maintenance schedule to periodically inspect and replace worn parts, maintaining equipment performance.

Professional Services

For complex faults, contact the manufacturer or professional technicians for repairs.

Brands and Models Repaired by Longi Electromechanical Company

1. Brookfield (AMETEK)
   • DVNext Series: DVNext Rheometer, DVNext Cone/Plate Rheometer
   • DV2T Series: DV2T Viscometer, DV2T Extra Viscometer
   • DV1 Series: DV1 Viscometer
   • CAP Series: CAP 2000+ Viscometer, CAP 1000+ Viscometer
   • R/S Series: R/S Plus Rheometer
2. Anton Paar
   • MCR Rheometer Series: MCR 72, MCR 92, MCR 102, MCR 302, MCR 502
   • RheolabQC: Compact Rheometer
   • ViscoQC Series: ViscoQC 100, ViscoQC 300
3. TA Instruments (Waters Corporation)
   • Discovery Series: Discovery Hybrid Rheometer (DHR-1, DHR-2, DHR-3)
   • AR Series: AR 2000ex, AR-G2 Rheometer
4. Malvern Panalytical
   • Kinexus Series: Kinexus Lab+, Kinexus Pro+, Kinexus Ultra+
   • Rotational Viscometers: SV-10, SV-100
5. Thermo Fisher Scientific
   • HAAKE MARS Series: HAAKE MARS iQ, HAAKE MARS iQ Air
   • HAAKE Viscotester Series: HAAKE Viscotester 1 Plus, HAAKE Viscotester 2 Plus
6. RheoSense
   • m-VROC: Microfluidic Viscometer
   • VROC Initium: Automated Viscometer
7. Cannon Instrument Company
   • Cannon CT-1000: Constant Temperature Bath
   • Cannon PolyVISC: Automated Viscometer
   • Cannon MiniQV-X: Rapid-Viscosity Analyzer
8. Fungilab
   • Smart Series: Smart L, Smart R, Smart Q
   • Viscolead Series: Viscolead ADV, Viscolead PRO
   • Alpha Series: Alpha L, Alpha R
9. Hydramotion
   • ViscoJet Series: ViscoJet 500, ViscoJet 700
   • ViscoSense Series: ViscoSense 300, ViscoSense 600
10. A&D Company
    • SV-A Series: SV-1A, SV-10A, SV-100A
11. Lamy Rheology
    • RM200 Series: RM200 Touch
    • RM100 Series: RM100 Touch
12. Grace Instrument
    • M5500: Automated Rheometer
    • M5600: High Temperature High Pressure Viscometer
13. PCS Instruments
    • MTM2: Mini-Traction Machine
    • ETM: EHD2 Traction Machine

Longi Electromechanical Company offers long-term repair services for viscosity meters, with nearly 30 years of experience in quickly repairing various instruments. Additionally, we recycle and sell various viscosity meters. Welcome to consult.