Flow Meter and Metering devices
At Liquid Handling Equipment, Inc. in Charlotte, NC, we also offer reliable flow meters and metering devices from Niagara Meters, which specializes in products for measuring liquids, steam and gases. Niagara Meters has produced flow meters for many industries since 1859 including agriculture, food & beverage, tobacco, mining, oil & gas, paper, petrochemical processing, plastics & rubber, pharmaceutical, as well as power generation.
Liquid enters the precision metering insert containing the turbine rotor. The liquid pressure drives the turbine rotor rate of rotation proportional to the volumetric flow rate. The rotor's rotation is magnetically coupled to and hermetically sealed.
A controlled magnetic field is applied to the metering tube by way of externally mounted coils. The conductive fluid flowing through the magnetic field generates a voltage at the sense electrodes that is proportional to the velocity of the fluid.
Flow is measured in terms of dynamic force acting on a target in the flow stream. A hermetically sealed strain gage is bonded in a bridge circuit configuration and mounted outside the flow stream. Electrical output that is proportional to the flow rate.
The 5600 Ultrasonic non-contact continuous system operates by transmitting an ultrasonic signal from the transducer to the surface of the liquid being measured. A reflection or echo is received, processed and the distance to the fluid is obtained.
The SmartPD meter is a digital volumetric meter that provides total volume and flow rate measurements by way of an electronic transmitter. This 2-wire device provides an analog response via 4-20 mA signal, digital feedback via HART® communication, and a visual indication of change on an LCD. The SmartPD meter is offered with two flow meters options; the nutating disc and the oscillating piston.
A nutating disc meter has a measuring chamber that contains a disc that nutates. The position of the disc divides the chamber into compartments containing an exact volume. Liquid pressure drives the disc to nutate causing the disc to make a complete cycle. The compartments are filled and emptied with each cycle. The movements of the disc are transmitted mechanically to a transmitter.
Liquid enters a precision-machined chamber containing an oscillating (rotating) piston. The position of the piston divides the chamber into compartments containing an exact volume. Liquid pressure drives the piston to oscillate and rotate its center hub. The movements of the hub are sensed through the meter cover by a follower magnet.
Liquid Flow Measurement
There are multiple methods used to measure the flow of a liquid.
Positive displacement (PD) flow meters measure the volumetric flow rate of a moving fluid by dividing the media into fixed, metered volumes (finite increments or volumes of the fluid). These devices consist of a chamber(s) that obstructs the media flow and a rotating or reciprocating mechanism that allows the passage of fixed-volume amounts. The number of parcels that pass through the chamber determines the media volume. The rate of revolution or reciprocation determines the flow rate.
Liquid enters a precision-machined measuring chamber containing a disc which nutates (wobbles). The measuring chamber contains an exact known quantity of fluid. Fluid pressure causes the disc to nutate and the control roller causes the nutating disc to make a complete cycle. The measuring chamber is filled and emptied each cycle. The nutations of the disc are transmitted by a gear train to a totalizer or pulse transmitter.