Product Overview
The Nakakita NS904 is an electronic vibrating-type viscosity transmitter designed for continuous fuel-oil viscosity measurement in marine engine rooms and industrial process systems.
A piezoelectric element generates torsional vibration within the detector. Changes in the fluid’s viscous resistance are converted into a 4–20 mA electrical signal, enabling integration with an electronic viscosity controller, automation system or data logger.
Technical Specifications
| Product information | Details |
|---|---|
| Manufacturer | Nakakita Seisakusho Co., Ltd. |
| Product series | NS904 |
| Detector model | NS904S |
| System/controller designation | NS904C |
| Product type | Electronic vibrating-type viscosity transmitter |
| Measuring principle | Viscous-resistance measurement using piezoelectric torsional vibration |
| Primary application | Marine fuel-oil viscosity measurement and control |
| Nominal sizes | 40A, 50A, 65A and 80A |
| Pressure ratings | JIS 5K–20K; ANSI Class 125–300 |
| Standard body materials | FCD400 or SCPH2 |
| Rated pressure | 2.0 MPa |
| Maximum fluid temperature | 180°C |
| Output signal | 4–20 mA DC |
| Standard measuring ranges | 0–30, 0–40 or 0–50 mm²/s |
| Equivalent viscosity unit | cSt |
| Detection accuracy | Within 2% of full-scale width |
| Minimum detectable viscosity | 0 mm²/s |
| Response time | Approximately 5 seconds |
| Approximate mass | 12 kg |
| Typical installation | Fuel-oil supply line near the heater and main engine |
| System integration | Electronic controller, control valve, alarm circuit or data logger |
| Suitable installations | Ships, offshore units, diesel power plants and industrial process systems |
Product Description
The Nakakita NS904 continuously measures fuel-oil viscosity by detecting changes in resistance acting upon an electrically generated vibrating element. Unlike a capillary transmitter, its measuring principle is particularly suitable for detecting low-viscosity fluids.
The transmitter sends a standard 4–20 mA signal to the vessel’s electronic viscosity controller. The control system can then regulate steam flow through the fuel-oil heater, maintaining the viscosity required for efficient engine combustion.
