Viscometer is used to measure viscosity resistance and absolute viscosity of fluids, including liquid, oil, food, medicines, adhesive, etc
Measuring range(mPa .s
Measurement error (Newton Liquid)
Operation Manual For NDJ-8S
NDJ-8S Digital viscometer is a new digital product based on the single chip micro-processor technologies and
used for determining the liquid viscose capacity and the absolute viscosity. Comparing with other similar
products, this instrument has the following features:
High measuring accuracy;
Stable in measured display;
Easy operation and read-out;
Excellent in Anti- interference.
NDJ-8S has been widely used to determine and measure the liquid viscosity in many
applications such as grease, painting, pharmacy and adhesives.
2 Main technical data
1) Measurement range: 1 ~2 x106 mPa•s;
2) Rotor types: 1#, 2#, 3# and 4# rotors;
3) Rotor velocity: 0.3, 0.6, 1.5, 3, 6, 12, 30, and 60 rpm;
4) Operation modes: manually or automatically select the rotor types and velocity.
5) Measurement error: ±2% (Newton liquid)
6) Dimensions: 370 mm X 325 mm X 280 mm (the base not included);
7) Net weight:6.8 Kg;
8) Operation conditions
a) Ambient temperature: 5°C~ 35°C；
b) Relative Humidity(RH): not greater than 80%;
c) Power supply: Voltage--220 V±10%, Frequency—50 Hz±10%;
d) No electro-magnetic interference, no severe vibration and no corrosion gases in
instrument surrounding area;
3 Working principle
1) The program-controlled motor rotates at the given velocity controlled by a program
and makes the rotary axis of the viscometer to revolve, and through a torque sensor,
then drives the standard rotors to rotate, the rotors will subject to a torque moment
proportional to liquid viscosity because of the liquid viscose hysterics. The torque
moment will be measured by the sensors and processed into the viscosity and
shown on the display. In order to extend the measuring range, 4 rotors with 8
different velocities were used in this instrument.
1. horizontal bubble 2.LCD screen 3.dustcloak 4. rotor protection bracket 5.Host base
6.Keyboard 7.Rotor connector 8.Rotor 9. horizontal adjusting knob
1) Take out the bracket and column from package, wrap the column in a nylon
washer,screw the column into the hole on the back of bracket and tight it by a
wrench to avoid loosen, put the tooth side of the column facing on the front of
2) Take out viscometer from package and mount the lifting clamper on the column,
adjust the clamping bolt to make the instrument moving up and down, and to
protect it drop down from column.
3) Loosen the protection bolt on the bottom of viscometer and take away the yellow
4) Check the horizontal bubble and adjust the screw for horizontal adjusting on the
bottom of bracket and make the bubble located on the central point, which means
instrument placed horizontally.
5) Connect power supply.
5 Operation procedures
1) Prepare the liquid to be measured and put it into a glass beaker or a right angle
Container with The diameter not smaller than 70 mm and the Height not lower than 125mm
2)take care of the liquid temperature, and keep the horizontal bubble in the middle.
3)according to measuring table, choose the right rotor and connect it on the rotor connector, turning right for
mounting, turning left for removing.
4) Adjust the lifting screw and put the rotor into the liquid to be measured till the level
mark on the rotor reach the liquid surface.
5) operation of Control panel
⑴ Put on the power supply switch ( on the back of the instrument ) put the instrument on stand-by state, the
Press to select English, then press OK to enter.
Before measuring, you should calculate the viscosity, Choose the right rotor and speed according to the
measuring range table, press OK, the rotor start to rotate, the instrument begin to measure.
(2) if you don’t know the right rotor and velocity, you can let the instrument to choose it automatically. Select
the smallest rotor #4 firstly, and press OK to start measure, the instruments will search the right velocity and
then show the measuring result and show the right rotor that need to be installed. Then install the right rotor to
measure again and it will show the right result. The higher the viscosity, the smaller rotor is used. The smallest
rotor is #4.
(3) instruments has alarm function, if the viscosity is over 100%, it will show OVER, it’s better to let the
measuring percentage range from 10% to 90% to get a more accurate result.
(4). to stop measure, you can press RESET button, to press OK, it will continue measure again.
NDJ-8S measurement range table
mPa. S velocity
60 30 12 6 3 1.5 0.6 0.3
1 100 200 500 1000 2000 4000 10000 20000
2 500 1000 2500 5000 10000 20000 50000 100000
3 2000 4000 10000 20000 40000 80000 200000 400000
4 10000 20000 50000 100000 200000 400000 1000000 2000000
1) This instrument is limited to the room temperatures, the temperature change should
be within ±0.1°C for a reliable measurement, or results could be severely effected.
2) This instrument should be used under the designed voltage and frequency and their
allowable error ranges, or incorrect results could be resulted.
3) Care should be taken for mounting or removing rotors, slightly and lift the connecting screw bolt to avoid a
transverse force acting on rotor to cause it bending.
4) The instrument with rotor mounted can not side-laid down or upwards down.
5) Keep cleaned on screws and connecting points between rotor and connecting bolt
rod, or a unstable rotation could be caused in the real measurement.
6) Use hand to hold the instrument when lifting up or moving down to avoid dropping it.
7) After completing measurement each time, the rotor should be fully cleaned (rotor
should be removed from instrument for cleaning), then place it on the protection
8) The instrument mounted with rotor should not be revolved without liquid to avoid
damaging the axis tip.
9) Unauthorized removing or replacing the instrument part, and applying lubricates
are not allowable.
10) When moving or shipping instrument, put on the yellow caver cap and lift the
connecting bolt rod and screw the bolt on the cap tightly. Attantion: the yellow pretection cap must be get off
before power supply
11) Suspension, emulsion or polymer and other high viscosity liquids are non-Newton
liquids, their viscosity will change with shear velocity and time, it is normal for
their measured inconsistent results under the selected rotor and velocity and time,
and it is not resulted from the instrument problems (in general, the rotor and
velocity and time should be specified for non-Newton liquids).
12) The cautions should be taken for followings to obtain a good measuring result:
⑴ Accurately control the temperature of liquid to be measured;
⑵ Ensure the ambient temperature unchanged;
⑶ Put the rotor immerged in liquid the unchanged temperature for enough time
under make its temperature same as liquid;
⑷ Ensure the liquid homogeneity;
⑸ Put the rotor located on the center of the liquid container in real measurement;
⑹ Remove bubbles adhered on the rotor when put it into liquid;
⑺ Use the settings close to full range as far as possible for measurement;
⑻ Use rotor protection bracket for measurement;
⑼ Ensure rotor cleaned;
⑽ Strictly follow the operation instruction for measurement.