NDJ-1 and NDJ-4 Rotational Viscometer are classic Dial-reading viscometers. Rotational Viscometers rotate a spindle within a fluid and measure the torque required to overcome the fluid’s viscous drag.
The NDJ-1/ NDJ-4 rotational viscometer is used to measure the viscous resistance and viscosity of liquids. It is commonly used to determine the viscosity of various fluids such as grease, paint, plastics, food, cosmetics, and adhesives. It is a precision instrument used by industrial and mining enterprises, universities, research institutes, and other units to monitor and improve product viscosity during production and research processes. It is an important means to stabilize and improve product quality.
Specifications
| Model | NDJ-1 | NDJ-4 |
| Viscosity range | 1 to 1×105 mPa·s | 1 to 2×106 mPa·s |
| Spindles | No.1, 2, 3, 4.
No.0 is optional, for low viscosity down to 0.1 mPa·s. |
|
| Speed | 6, 12, 30, 60 rpm | 0.3, 0.6, 1.5, 3, 6, 12, 30, 60 rpm |
| Accuracy | ±5% F.S. (Newtonian fluid) | |
| Power | 220V±10%, 50Hz | |
| Net weight | 1.5 kg | |
| Dimensions | 400×370×150 mm | |
Working Principle
The NDJ-1/ NDJ-4 rotational viscometer is powered by a stepper motor that rotates at a stable speed, connected to a graduated disk. This motor, via a hairspring and shaft, drives the spindle. If the spindle experiences no resistance from the liquid, the hairspring, pointer, and graduated disk rotate at the same speed, and the pointer indicates a reading of “0” on the dial. On the contrary, if the spindle experiences viscous resistance from the liquid, the hairspring generates torque, which counteracts the viscous resistance, reaching equilibrium. In this case, the pointer connected to the hairspring indicates a specific reading on the dial (i.e., the hairspring’s twist angle). Multiplying this reading by a specific coefficient gives the viscosity of the liquid.
Features
- The instrument’s rotational speed is adjusted via a gear system and clutch through a speed control knob, offering four speed settings to be selected according to the measurement requirements.
- The instrument comes with four spindles (sizes 1-4) or five spindles (sizes 0-4) depending on the specifications (spindle size 0 is optional). The appropriate spindle can be selected based on the viscosity of the liquid being measured and the corresponding rotational speed.
- The instrument is equipped with a pointer locking mechanism for accurate readings. When the rotational speed is high (30 rpm, 60 rpm), it may be impossible to take a reading while rotating. In this case, gently press the pointer locking lever to lock the pointer, and then turn off the instrument to take the reading.
- The spindle guard is for stabilizing the measurement and protecting the spindle. Using the spindle guard ensures more stable measurement results.
- The instrument is equipped with a fixed stand and a lifting mechanism, generally used in laboratory settings for small-volume and constant-temperature measurements. Fixing the instrument to the base ensures measurement accuracy.
- Spindle size 0 is used for measurements below 20 mPa·s as a reference.
- This instrument features a gear and damping lifting mechanism, ensuring smooth lifting.
- The entire instrument is well-packaged for shock protection to ensure its precision.
Please contact us for technical consultation and a quote.