Liquid Density Analyzer DM8C, VD6

In 1967, Yokogawa developed the model VD6 vibration type liquid density analyzer in response to user requests for an online density analyzer that could be used in process automation. This was an important development in the instrumentation field, because density is a fundamental physical quantity, and its accurate measurement is important to almost all processes. The VD6 density analyzer has gone on to develop an excellent reputation as a highly stable, high sensitivity meter.

The new DM8 vibration type liquid density analyzer is a highly reliable, multi-function meter that builds on the experience gained with the VD6. It takes advantage of the latest computer technology to integrate a wide range of sensor techniques. Its converter incorporates a microprocessor that directly converts sensor frequency signals into density values for display. It is provided with a variety of functions such as one-touch calibration, self diagnosis and digital output (RS-232C).

The DM8 is a vibration type liquid density analyzer and its converter incorporates a microprocessor to directly convert frequency signals from the sensor into density values and display them and is provided with a variety of functions such as one-touch calibration, self diagnosis, digital output.

The DM8 liquid density analyzer measures liquid density of general process liquids with high sensitivity and excellent stability. It has a measuring density range of 0 to 2.0 g/cm3, and unaffected by flow rate and viscosity. Besides general-purpose sensor, sanitary and explosionproof sensor are also available.


  • High sensitivity and stability.
  • One touch calibration with a standard calibrating solution.
  • Free setting of measuring range in the field.
  • Failure alarm display and output.
  • Outdoor installation of converter.
Measurement object Liquid density
Measurement principle Vibration density measurement
Measurement range Density :0.5 to 2.0 g/cm3
Measuring liquid temperature -10 to 100℃
Measuring liquid pressure 2 MPa G or less
Withstandable pressure 4.9 MPa G
Output signal Analog output:4 to 20 mA DC (load resistance 550 Ω or less), and 0 to 1 V DC (load resistance 250 kΩ or more), isolated output.
Digital output: RS-232C
Output signal span 0.05 to 0.5 g/cm3 settable
Reference temperature set range 0 to 100℃ (in increments or decrements of 1℃)
Contact output on failure One output
Settable range for temperature coefficient 0 to 0.002 g/cm3/℃
Calibration procedure One-touch calibration by strong calibration liquid density (one-point calibration)
Ambient temperature -10 to 55℃
Case construction Dust and rain proof construction
Power supply 90 to 132 V AC or 180 to 264 V AC, 50/60 Hz
Weight Approx. 7.5 kg (Converter), approx. 12.0 kg (Detector)

Overall performance after combining the detector and converter.

Linearity ±0.5 % of span (when span is 0.2 g/cm3 or less)
Repeatability 5 x 10-4 g/cm3 (for digital output)
1 % of span (for analog output)



One of the critical control points in the brewing process is the monitoring of the progress of the fermentation stage. The DM8 Vibration Type Liquid Density Meter offers high sensitivity and stability, realizes precise control, reduces workload, and reduces instrument costs.


Caustic soda and hydrochloric acid, produced in electrolyzer plants, are fundamental materials used in varieties of industries; chemicals, pharmaceuticals, petrol-chemicals, pulp and papers, etc. Profit is the result of the effective production with minimized running / maintenance cost. Proper control of the process brings you stabilized quality of products with the vast operational profit.


Process liquid analyzers such as pH meters, conductivity meters, ORP meters, and density meters play an important role at electrolysis plants in the control of concentrations of various process solutions. This requires both precision and stability under harsh conditions that include highly corrosive substances, high temperatures, and many impurities.


Caustic soda is an important basic material in the chemical industry and is mainly produced by the electrolysis of soda. In the electrolysis process to make concentrated caustic soda, the DM8 Liquid Density Meter ensures high product quality through accurate measurement of liquid density.


In the food industry, the control of concentrations on the production line is critical to product quality, determining, among other things, how good the food tastes. One such procedure for doing this involves taking a sample from the production process and measuring its specific gravity (density) with a hydrometer. 


Skim milk is what remains after cream is removed from raw milk. Cream is removed to bring the fat content of the skim milk as close as possible to the lower limit of a designated range. For this purpose, control of the fat content in the cream and the skim milk is essential. The fat content in the cream and the milk has a direct relationship to their density and is controlled by the measurement thereof. 





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