Litre Meter specialise in the design, manufacture and supply of flowmeters. Over the years the VFF rotary piston flowmeter has proved capable of measuring methanol at 0.407 cP up to oil at 5000 cP. Listed below are all the flow meters within our range that are suitable for high and low viscosity liquids:
Positive displacement flowmeters, also known as PD meters, measure volumes of fluid flowing through by counting repeatedly the filling and discharging of known fixed volumes. A typical positive displacement flowmeter comprises a chamber that obstructs the flow. Inside the chamber, a rotating/reciprocating mechanical unit is placed to create fixed-volume discrete parcels from the passing fluid. In the VFF the rotor is basically a disc shape with an annular groove on its underside capable of holding and transporting flow from the chamber inlet to the outlet i.e. a rotary piston. The units are manufactured in 316 stainless steel or titanium. They can measure pulsing flows. Suitable for a wide range of process liquids and viscosities. 0.01 to 33,000 l/hr. +/-0.5% accuracy, +/-0.25% repeatability.
Vortex and other types of "oscillatory" flow meters utilize the behaviour fluid oscillations in order to derive flow rate. This technology works by inducing fluctuations in the fluid properties such as pressure, density or viscosity which can be converted into a flow rate. These flowmeters are normally calibrated on water. No moving parts and relatively tolerant to particulate flow these find many applications where temperatures are high or where other more traditional flowmeter technologies are out of spec. +/- 1% rate, 1/2" to 8" and insertion.
Ultrasonic flowmeters measure the travelling times (transit time models) or the frequency shifts (Doppler models) of ultrasonic waves in a pre-configured acoustic field that the flow is passing through to determine the flow velocity. The Sierra range of ultrasonic (transit time) Innovasonic devices are available, click for details. Litre Meter has access to other ranges but the Innovasonic is relatively unique as not only are fixed and portable ultrasonics available but also insertion devices for tougher applications. Ultrasonic flow meters can measure water and other liquids over a range of velocities & viscosities and with a certain amount of solid content. 25mm to 10000mm;±1.0% of reading (also 0.5%); 0 to ±40 ft/s (0 to ±12 m/s).
Magnetic flowmeters, also known as electromagnetic flowmeters or induction flowmeters, obtain the flow velocity by measuring the changes of induced voltage of the conductive fluid passing across a controlled magnetic field. The fluid has to be conductive so tap water and waste water are OK. Care has to be taken in measuring solvents, hydrocarbons, de-ionised and demineralised water where electromagnetic flow meters are not normally used due to low conductivity. Contact Litre Meter for full details. 3mm to 2000mm although insertion units can be used up to 3000mm. ±0.2% over flow range 0.5 to 5 m/s; turndown 1000:1; maximum velocity 10 m/s.
Positive displacement flowmeters, also known as PD meters, measure volumes of fluid flowing through by counting repeatedly the filling and discharging of known fixed volumes. A typical positive displacement flowmeter comprises a chamber that obstructs the flow. Inside the chamber, a rotating/reciprocating mechanical unit is placed to create fixed-volume discrete parcels from the passing fluid. The helical screw principle uses 2 counter rotating gears to form a continuous constant volume cavity. The OMK is a stainless steel version suitable for water flow metering. 0.2 to 100 litres per minute, +/-0.5 to +/-2% accuracy, +/-0.2% repeatability. OMG and OME versions in steel and aluminium can be selected for suitable process liquids and viscosities; +/-0.1 to +/-0.3% accuracy, +/-0.01% repeatability. 0.1 to 7500 l/min.
