CMT-30 & CDT-30 Liquid Mass and Density Systems




Accumass - CMT-30 Illustration

















CDT-30 System Constructed of Hastelloy and Plastics for Acid Service

CMT-30 Continuous Mass Transmitter
  • Highly Accurate Liquid Mass measurement without the need for temperature compensation. 
  • Sectioned Displacer Design for ease of Shipment and Installation
  • Process Compatible Materials
  • Not Sensitive to Wave Action.
  • Single Point Analog Output
  • Multi Point Microprocessor based Monitoring

Operation of the CMT-30 / PM-4000 AccuMass System begins with the CMT-30 Transducer / Displacer Assembly. This Assembly is generally mounted by means of a flanged connection at the top of the Vessel requiring measurement. The Standard mounting flange is 6” 150# . Consult Factory for other sizes and options. The Displacer element hangs from a Hermetically Sealed Transducer, and extends the entire length of the Vessel.This displacer consists of a sealed uniform cylinder whose diameter and weight depend on the following variables:

  1. Specific Gravity at Standard Conditions for the measured fluid.
  2. The Vessel Height.
  3. The size of the Flange in which the displacer must be inserted.

Zero Measurement is an empty tank with the displacer completely suspended in air. As the liquid rises and covers the displacer, it becomes more buoyant. The weight that the Transducer senses becomes less in direct proportion to the linear distance covered and the Specific Gravity of the Fluid at Standard Temperature and Pressure. This method of measurement (known as an inferential method) is extremely useful in determining the amount of liquid by weight in a vessel.

EXAMPLE:As a product in a vessel expands with temperature increase, the liquid level on the displacer will increase in height, and the specific gravity of the fluid will proportionately drop. The displacer however will not indicate any change because the total weight of this mass of fluid in this vessel has not changed. Therefore there is no need for temperature compensation of measured values because the displacer sees the weight of the fluid it displaces and not the height.The AccuMass system will directly measure the Liquid Mass within the Vessel.

CDT-30 Continuous Density Transmitter

The CDT-30 Accuden system closely resembles the CMT-30 Mass System described above. The major difference is that the CDT-30 displacer must be completely covered and that the instrument measures Liquid Density (Specific Gravity)   instead of Mass.

Displacers are generally constructed in shorter lengths, and installed in tanks or bridle chambers that remain full.  The vessel on which the CDT-30 system is installed  usually  has a low flow entering from the bottom of the vessel, and overflowing into an outlet line near the top of the vessel. Utilized in this way, the CDT-30 can continuously sample Liquid Density.

CDT-30 Systems have been applied in applications ranging from Tomatoe Paste density to measuring Hydrochloric Acid concentrations in a range as low as .05 Specific Gravity.


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