Viscometer – Operation and Calibration Procedure

Standard Operating Procedure (SOP) for Operation and Calibration of Brookfield make Viscometer used to determine the viscosity of solution / suspension / liquids in Quality Control department.

Viscometer (Brookfield) – Operation and Calibration Procedure

1.0   Objective :

    • To lay down a procedure for operation and calibration of viscometer. It is used to determine the viscosity of solution / suspension / liquids.

2.0   Scope :

    • This SOP is applicable for operation and calibration of viscometer (Make: BROOKFIELD;  Model : DV-I+) in Quality Control

3.0   Procedure – Viscometer:

    • What is Viscosity ?

    • Viscosity is a measure of a fluid’s resistance to flow.
    • It describes the internal friction of a moving fluid.
    • A fluid with large viscosity resists motion because its molecular makeup gives it a lot of internal friction.
    • A fluid with low viscosity flows easily because its molecular makeup results in very little friction when it is in motion.
    • Gases also have viscosity, although it is a little harder to notice it in ordinary circumstances.
    • Operation Procedure for Viscometer:

    • Ensure that equipment is clean.
    • Check the level of instrument with the help of spirit level on the top of the Viscometer, and if required set level with help of three screw on triangle bottom.
    • Check the connection of  electric  supply behind thermistor plug with temperature probe (socket) on posterior panel.
    • Clean the spindle which you have to use and maintain the temperature of liquid as required.
    • Put ON the electric supply and switch on the switch of instrument at the posterior left.
    • Wait for some time, screen will instruct for PRESS ANY KEY. Press any key.
    • Screen will show % , spindle code, RPM, Viscosity (cps) and Torque (%).

    • For selecting the spindle code (as per requirement) press buttons SELECT SPINDLE .
    • Blowing start for change in press UP arrow and DOWN arrow and when desired number comes on   screen, again press SELECT SPINDLE. Blowing will stop.
    • For setting RPM ( as per required) press SET SPEED ,  set number by using up and down arrow, again press  SET SPEED.
    • Fit the spindle (as per requirement) in horizontal screw pin by clock wise rotation carefully (up to spindle mark).
    • Move the spindle up with screw on horizontal stand and place beaker having liquid below the spindle down for immersing the spindle head in liquid completely (up to spindle mark).
    • Press the red switch MOTOR ON/OFF.
    • Spindle will start rotating; press the SELECT DISPLAY again and again screen will express the reading %, mPas, SS, SR, reading one by one.  Note the reading as per requirement.
    • After completion of work clean the spindle and place it properly.
    • Switch OFF the equipment.
    • Enter the details in Instrument log .
  • Calibration Procedure of Viscometer :

    • Calibration of viscosity:

    • Operate the viscometer as per SOP.
    • Use the spindle No 1, and Viscosity Standard as per given below table.
    • Check the temperature of solution and it should be between 25 ± 1°C.
    • Take average of three readings.


Spindle No RPM Viscosity of Standard Solution (cps) Tolerance


1 1 6 As per Standard value ±2%
2 1 50 As per Standard value ±2%
3 1 100 As per Standard value ±2%
    • Enter the details in Annexure I.
    • Enclose the old calibration tag with the record and don’t throw it.
    • Calibration of RPM :

    • RPM calibration shall be done by external agency for 6RPM, 50 RPM, and 100 RPM.
    • Acceptance criteria:  6 RPM ± 1RPM , 50 RPM ± 1RPM ,100 RPM± 2RPM
    • If the variation is not within the specified tolerance limits:
    • Inform to the Department Head.
    • Do not use equipment until all errors are rectified.
    • After rectification, again calibrate the equipment & record the observation.
    • Frequency of Viscometer Calibration:

    • Calibration of Viscosity: Monthly ± 3 days.
    • Calibration of RPM        : 6 Months ± 15days.
    • Important:
    • Liquid must be free from air bubble.
    • Spindle must be in middle of the liquid.
    • Check carefully the Temperature, the Spindle code and the RPM.
    • If any problem exists in the equipment inform to the service engineer.
    • For more details refer instruction manual

Annexure-I : Calibration Record of Viscometer

Make  : ………………….           Eq. No. : ……………………                 Model No. : ……………….                    

Viscosity:                                                                        Calibration Frequency : Monthly ± 3 days                                                                 



Spindle No. RPM Actual viscosity of Standard Solution (cps) Observed Viscosity Average Tolerance


1 1 6 ±2%
2 1 50 ±2%
3 1 100 ±2%

Calibration done on: …………………                                   Next calibration due on : ……………………….

Spindle RPM:                                                                 Calibration Frequency : 6 Months ± 15 days

Calibration done on :  ………………………..                         Done by      : ………………………

Calibration report No. :  ………………………                       Next calibration due on : ………………………

Remarks: The observed values comply / does not comply the acceptance criteria and the equipment can be / cannot be used for routine analysis.


Manufacturer manual

SOP : Status Labeling

SOP : Filling of Instrument Log


SOP                :           Standard Operating Procedure.

QC                  :           Quality Control

QA                   :           Quality Assurance

Cps                  :           centipoises

°C                    :           Degree Centigrade

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