1. Pour the tested sample into a circular flat-bottomed container with a diameter not less than 70mm. ( Special container and SNB-1A/NDJ-1C viscometer should be used for the test of No. 0 rotor )
2. Install the rotor protection bracket on the lower cover of the instrument. (Installation method: insert the two round holes at the upper end of the protective frame into the fixed shaft of the lower case, and then turn it counterclockwise)
3. Select the applicable rotor and screw it clockwise to the lower shaft joint.
4. Turn the lifting knob to lower the instrument slowly, immerse the rotor into the sample and keep the liquid level marking line (groove or convex line on the rotor rod) level with the measured liquid level.
5. Check again whether the spirit level in front of the instrument is level.
Note: When loading and unloading the rotor, do not pull the shaft joint downward or laterally to avoid damage to the internal structure.
During the test, the ambient temperature needs to be constant to ensure the stability and accuracy of the measured value.
Precautions
1. Since viscosity is a function of temperature, when the instrument is working at room temperature, the temperature fluctuation should be controlled within ±0.1°C, otherwise it will affect the accuracy of measurement. A constant temperature bath can be used if necessary.
2. Keep the rotor surface clean.
3. Since the hairspring has a certain linear region, please pay attention to the torque % value when measuring, which should be between 10% and 95%. When the % value is too high, the viscosity will display the overflow symbol "EEEEEE". Replace the rotor or change the speed, otherwise it will affect the accuracy of the measurement.
For example: test the sample with NDJ-8S type viscometer, use the No.1 spindle and 60 revolutions per minute combination test , if the viscosity shows "EEEEE", then the speed should be reduced. If the viscosity , it should be tested with a smaller rotor (smaller surface area). For example, when the tested samples are in the same rotor condition, the % values at different speeds are all between 10% and 95%. Whichever is the larger percentage is taken. Other models of machine test and so on.
4. Be careful when loading and unloading the rotor, lift the universal joint slightly upwards, and do not use too much force. Do not force the rotor laterally and never pull the rotor down to avoid damage to the shaft tip.
5. Since the connection between the rotor and the universal joint is left-hand thread, please remember the direction of rotation (as shown in Figure 13) when loading and unloading the rotor , so as not to damage the universal joint.
6. The universal joint should be kept clean.
7. The instrument should be lowered slowly, and it is better to hold it by hand to avoid damage to the axis due to vibration.
8. When the instrument is being transported or moved, the universal connector should be covered with a protective cap.
9. Many suspensions, emulsions, polymers and other high-viscosity liquids are "non-Newtonian" liquids, and their apparent viscosity values change with shear speed and time, so in different It is normal for the results to be inconsistent when measuring the rotor, rotational speed and time . (For example, the results of measuring non-Newtonian fluids will have certain deviations even under the same rotor and the same speed) This is all determined by the nature of the fluid, not a problem with the instrument test.
