NDJ-79 rotary viscometer is a kind of measuring the absolute viscosity and
A precision instrument for the apparent viscosity of Newtonian liquids. If used with a specific rotor, it can also determine the rheological properties of non-Newtonian liquids. It has the advantages of convenient use, stable performance, and simple maintenance. It is suitable for measuring various oils, paints, inks, coatings, plastics, slurries, rubber, latex, detergents, resins, condensed milk, cream, drugs, and cosmetics. The viscosity of the fluid is a necessary instrument for the laboratories and analysis rooms of textile, chemical, petroleum, electromechanical, pharmaceutical, food, light industry, construction, and other industries, as well as universities and colleges, scientific research units, and military departments.
How the instrument works
The instrument is driven by a miniature synchronous motor, which rotates at a constant speed of 750 r/min, and is hardly affected by changes in load and power supply voltage. The housing of the motor is installed in a suspended manner. It drives the rotating drum to rotate through the rotating shaft. When the rotating drum rotates in the liquid to be measured, it is subjected to viscous resistance, thereby generating a reaction force that deflects the motor housing. The motor housing is connected to two The positive and negative metal balance springs are connected, and the rotation of the case causes the balance springs to generate torque. When the torque of the balance spring and the viscous resistance torque are balanced, the pointer connected to the motor case will point out a certain value on the dial, which is proportional to the viscous resistance of the drum, so the scale reading is multiplied by the rotation The barrel factor represents the magnitude of the dynamic viscosity.
test unit
NDJ-79 rotary viscometer is attached with two kinds of test units, each unit includes a measuring container and several rotating cylinders with rotating shafts.
The second unit has three cylindrical drums (1'', 10'', 100''), specially treated brass tubes, 1'' is the thickest and 100'' is the thinnest. There is a water-proof jacket in the measuring container, which can pass constant temperature water. There are two screw holes in the upper part of the measuring vessel, one for inserting a bimetallic thermometer, the other is sealed with a screw plug, or a glass thermometer with suitable seals can be inserted (but not supplied with this unit). Suspending the drum is a left-handed knurled nut with a hook.
The third unit has four cylindrical drums (0.1'', 0.2'', 0.4'', 0.5''), specially treated brass tubes, 0.1'' is the thickest, 0.5'' is the thinnest . There is a long cylinder with a water-proof jacket inside the measurement container, and a special bracket for installing a bimetallic thermometer. The constant temperature water flows through the bracket first, and then flows into the measurement container of unit III. The bimetallic thermometer and hook knurled nut are shared with the second unit.
Instructions for use
1. How to disassemble the shock absorber (see Figure 2):
2. Power supply:
The power supply voltage of this viscometer is 220V, the frequency is 50Hz alternating current, the voltage in the instrument after transformation
Reduced to (24V~30V). When the instrument is powered on, the power cord is first connected to the instrument and then plugged into the power socket.
3. Left-handed knurled nut (anti-thread) connection:
Measuring unit | factor | Speed r/min | Range and scale value mPa·s | Cut cut speed Rate s-1 | Sample amount ml | |
Measuring range | every Scale value | |||||
II | 1 | 750 | 10~100 | 1 | 2028 | 15 |
10 | 100~1000 | 10 | 344 | |||
100 | 1000~10000 | 100 | 176 | |||
F10×100 | 75 | 10000~100000 | 1000 | 18 | ||
F100×100 | 7.5 | 100000~1000000 | 10000 | 2 | ||
III | 0.1 | 750 | 1~10 | 0.1 | 3550 | 70 |
0.2 | 2~20 | 0.2 | 1855 | |||
0.4 | 4~40 | 0.4 | 1006 | |||
0.5 | 5~50 | 0.5 | 836 | |||
Units II and III use left-handed knurled nuts with hooks. When dismounting the left-handed knurled nut, insert a thin rod with a diameter of 3mm into the small hole on the side of the bakelite disc, so that the motor shaft is stuck, which makes it easy to screw on or remove the left-handed knurled nut.
1. Zero point calibration (zero adjustment)
When the viscometer leaves the factory after debugging and verification, the position of the pointer should be between 5 and 10 grids. When zeroing, the motor should be rotated without load, and the zeroing screw should be screwed in gently, and the pointer will slowly return to zero at this time. If the pointer has returned to the zero point, the zero adjustment screw cannot be screwed in again. At this time, it should be unscrewed in the opposite direction, otherwise the zero adjustment spring is easy to break, please pay attention. The zero point calibration during the test should be repeated three times under no-load when the machine is turned on, and the zero point is confirmed to be correct, and then the zero point adjustment is completed and the test can be carried out. After the test, the zero adjustment screw should be withdrawn.
2. The connection of the drum:
The rotating elements of units II and III are attached with steel wire shaft hooks, and the motor transmits the torque to the rotating drum through the hook shafts. This method is used to avoid twisting the hooks.
The drums of units II and III are connected to the rotating shaft through the U-shaped spring that has been located in the drum. The hook shaft pulls out the U-shaped spring from the drum to remove the drum. When reinstalling the drum, it should be The two ends of spring stretch to get final product in the tube.
Each unit test method:
(1) Determination of Unit II:
Unit II (see Figure 3), which is used for precise determination of high viscosity. It has three standard tumblers with respective factors of 1, 10, and 100. About 15ml of fluid is required for the test. The measuring range of each drum is shown in Table 1.
Table 1 Measurement range of II unit
The viscometer multiplies the scale reading by the factor of the drum used, and the viscosity value expressed in mPa·s can be obtained.
Test steps:
将被测的液体小心倒入测试容器，直至液面达到锥形面部边缘，再将转筒插入液体直到完全浸没为止，然后把测试容器安放在仪器托架上，并将转筒挂钩悬挂于仪器左旋滚花螺母的挂钩上。这时启动电机，转筒旋转并从开始晃动到对准中心，为加速对准中心可将测试器在托架上前后左右微量移动，当指针稳定后可读数。如果读数小于10格，应当调换直径大一号的转筒。
使用减速器进行测定：
用第II单元测定高粘度溶液时（超过10000 mPa·s），可使用两个作为附加装置的减速器，其速比为1：10和1：100，这时使转筒的旋转速度相应在减为原值的1/10和1/100，即转速降为75r/min和7.5r/min。
1：10和1：100的减速器各自的因子分别为10和100，且只适用于因子为100的转筒，最细的100#.测量范围见表2。
表 2 加速器的测量范围
使用减速箱后粘度值的计算：即转筒因子乘以减速器的因子再乘以刻度读数便得到用mPa·s为单位的粘度值。
减速器的安装与固定：
将减速器输入端的联轴节套入电机输入轴，且于电动机输入轴上的联轴节相啮合，并通过滚花螺栓将减速器固定在细杆端部（细杆位于电动机轴后向下突出），拧紧螺栓对应使减速器刚好处于水平位置。然后将左旋滚花螺母旋于输出轴上，并重新调整零点。
（2） 用第III单元测定：
第III单元（参见图4），它用于低粘度的精准测定，本单元有四个转筒，每个转筒的因子分别为0.1、0.2、0.4、0.5.
测试需要的液体约为70ml。各转筒测量范围见表3.
表 3 II单元测量范围
粘度值为所用转筒的因子乘以刻度读数，便得到以mPa·s表示的粘度值。第III单元不可同减速器一起使用。
测定步骤：与第II单元相同。
表 4 各测量单元对应表
注意事项
1、 本粘度计为精密测试仪器，使用前请详细阅读本说明书，在使用维护中需要严格遵守说明书中所规定的条件及步骤进行工作。
2. The instrument needs to be used within the specified voltage (220V±10%) and frequency (50Hz), otherwise it will affect the speed and measurement accuracy. If the grid frequency is not 50Hz, the actual viscosity needs to be obtained according to the following correction formula.
50Hz
Actual viscosity = indicated value viscosity × ————————
Grid frequency used
3. The power cord needs to be plugged into the instrument first and then powered on.
4. After turning on the start switch of the motor, if the motor fails to start in time, the switch should be turned off immediately and restarted.
5. The motor should not be used continuously for a long time, generally not more than 4 hours.
6. The instrument has been debugged and calibrated and verified by the metrology department before leaving the factory. Therefore, the internal parts of the instrument are not allowed to be disassembled at will, and the balance spring is strictly prohibited.
7. When the instrument leaves the factory, the agate bearing should not be shattered during transportation, so it is equipped with a shock absorber, which can be removed when it is used.
8. Before and after use, the drum and the inner wall of the measuring device should be cleaned and dried to ensure the measuring accuracy of the instrument. The U-shaped spring hanging rings of the rotors of the II and III measuring units can be pulled out to clean the inside and outside of the rotors, and then insert the springs.
9. Do not use too much force when disassembling the coupling, insert the insert rod first, and then install and disassemble the counter-tooth knurled nut.
10. The instrument should always be kept dry when stored.
