South African manufacturer Instrotech is offering a flowmeter called Kobold RCD, for measuring and monitoring the flow of liquids and gases.

The company explains that, depending on the model, the measuring range of the Kobold RCD ranges from 0.5 ℓ/min to 2 350 ℓ/min for water and 0.5 Nm3/h to 2 750 Nm3/h for air with connections G1/2 to G3 for liquids, ½" NPT to 3" NPT for gases. It can also be used to measure or monitor other liquids and gases.

The company explains that the functional principle behind the Kobold RCD meter is the Venturi tube. The device consists of a tube that first narrows and then expands; the pressure difference between the inlet of the narrowed area and the narrowest area allows the flow to be determined.

“Within the housing, passages register the resulting differential pressure and transmit it to a bellows system in the display housing. The bellows system is protected by stop pins whenever the maximum rated flow is exceeded,” the company highlights.

It points out that, with mechanical displays, the flow value measured by the bellows system is transferred to the calibrated display – in ℓ/min for water and N/m3/h for air – and indicated by means of a pointer element. With electronic displays, a Hall sensor converts the mechanical movement into an electrical signal. The strength of this signal varies with the flow.

Various electronic systems are available to display or monitor and evaluate the flow volume. It says that specific display scales are available for use with any media at any pressure and temperature. The Kobold RCD flowmeter is appropriate for use in the areas of machinery, plants, chemicals and pharmaceuticals industry, heavy industry, as well as the beverage and luxury-food industries.

Special advantages of the unit are that it has no moving parts, has a universal mounting, is self- monitoring and has easy operation. Measurement accuracies are 3% of the upper range value, with a reproducibility of 1%, also of the upper range value.

The company concludes that the maximum service temperature is 100 ºC for a needle indicator and 80 ºC for an electronic display.