The Comprehensive Flowmeters Resource

Rotameter yokogawa The RAMC Rotameter


The short-stroke Rotameter RAMC allows the measurement of high flow rates using a relative short metering tube. It is a stainless-steel armoured construction for the safe measurement of a variety of liquids, gas and steam. Its special application is for hazardous, dangerous or aggressive fluids, for high temperatures and high-pressure rates. The instrument is mounted in a vertical pipeline with flow direction upwards.

The RAMC is a metal Rotameter featuring an electronic transmitter and Hart communication that offers a high degree of safety thanks to the patented float blockage detection function. If the sensor signal shows no movement of the float despite a fluid flow, an alarm signal is generated and an error message output. RAMC meters with float blockage detection have been used in safety instrumented systems satisfying SIL 1 requirements as defined by IEC 61508 since 2005; RAMC models with a local indicator and inductive limit switches are employed in SIL 2 applications.

The insertion of a temperature spacer between the metering tube and the indicator enables the RAMC to be used across a wide process temperature range from -200 to +370 °C. It is thus suitable for measuring not only cryogenic media such as liquid nitrogen but also hot oils or superheated steam in petrochemical processes. If required, the RAMC can additionally be equipped with a heating jacket for heat transfer fluids such as steam, hot water, oil or special liquids, where heat losses are undesirable and there is a risk of crystallisation at low ambient temperatures. A comprehensive set of approvals for use in hazardous areas is available for types with a local display and inductive limit switches as well as those with an electrical output signal (4…20 mA, Hart or Profibus PA).


  • Patended float blockage detection
  • Suitable for applications according to IEC 61508 and ISO 13849
  • Intrinsically safe outputs or explosion proof housing available
  • Spacer for high/low temperature applications
  • Special material like Monel and Hastelloy on request
  • Easy to install and maintain.
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