Operating, Cleaning and Calibrating Procedure for Viscometer

1. OBJECTIVE
To lay down the procedure for operation, cleaning and calibration of Viscometer

2. SCOPE
This procedure is applicable to Quality Control Department

3. RESPONSIBILITY
• Officer QC
• Manager QC

4. SAFETY INSTRUCTIONS
• Proper handling the instrument.
• Don’t switch on the main board with wet hands

5. PROCEDURE
5.1 OPERATION
5.1.1 Mount the guard leg, if used, (Spindle Protector) on the viscometer.
5.1.2 Attached the spindle (left-hand thread) to the viscometer lower shaft by lifting the coupling screw slightly. Hold it firmly with one hand while screwing the spindle on with other (note left-hand thread). Avoid putting side thrust on the shaft.
5.1.3 To avoid trapping air bubbles under the disc-type spindle, do the following before attaching the spindle. Being by immersing the spindle in a diagonal path, slowly drag the spindle across the fluid surface, and bring the spindle to an upright position and thread on to screw.
5.1.4 Lower and center spindle in the test material (600ml beaker) until the “meniscus” of fluid is at the center of the immersion groove on the spindle’s shaft.
5.1.5 To make a viscosity measurement, turn the motor switch “ON”. This energizes the viscometer drive motor. Allow time for the indicated reading to stabilize. This time required for stabilization will depend on the speed at which the viscometer is running and the characteristics of the sample fluid.
5.1.6 When making a viscosity measurement, the reading should be noted and divide by factor appropriate to the viscometer model/spindle/speed combination being used. Refer to the table below or to the FACTOR FINDER for calculating viscosity. For maximum accuracy, readings below 10.0% torque (dial reading) should be avoided.
5.1.7 Turn the viscometer motor switch “OFF” when changing a spindle, changing samples etc. Remove spindle.

1 2 3 4
6 10 6 50 6 200 6 1K

12 5 12 25 12 100 12 500
30 2 30 10 30 40 30 200
60 1 60 5 60 20 60 100
= Spindle = Spindle Speed = Factor K=1000

5.2 CLEANING
5.2.1 After completion of testing switch “OFF” the instrument.
5.2.2 Switch “OFF” the mains.
5.2.3 Remove the spindle from the instrument.
5.2.4 Clean the spindle with respective solvent in which solution of sample is prepared.
5.2.5 Clean the spindle with methanol.
5.2.6 Wipe it with tissue paper.
5.2.7 Place the clean spindle at its respective place in the box.
5.2.8 Clean the instrument with a cotton cloth.

5.3 CALIBRATION
Frequency: Once in three months
5.3.1 Operate the instrument as per SOP.
5.3.2 Calibrate the instrument with standard viscosity solution of 1450 cps using respective spindles
5.3.3 The performance of instrument is satisfactory, If the measured viscosity is within the given tolerance limit, otherwise follow the SOP

6. RELATED DOCUMENTS
Operational Log Book Format – Annex. I
Cleaning Log Book Format – Annex. II
Calibration Report Format – Annex. III

7. DISTRIBUTION INDEX
Original Copy will be retained by Quality Assurance Department.

8. ABBREVIATIONS
Q.C Quality Control Department
SOP Standard Operating Procedure

9. REVISION HISTORY