Kobold LFM Dual Ring Piston Pendulum

Kobold LFM flow rate measuring transducer suitable for use in filling and batching processes with all types of low viscosity liquids. It can be used for extremely low volumetric flow rates >0.005 l/min.

Kobold LFM Dual Ring Piston Pendulum

Kobold LFM Method of Operation

The measuring mechanism is based on a dual-ring piston pendulum. The right-hand measuring chamber is opened, and the left-hand chamber closed, by the pendulum arm that is inclined to the right. The pressure of the forced liquid acts on the upper surface of the piston pendulum. The right-hand ring piston is pressed clockwise downwards, and the lefthand ring piston is pressed clockwise upwards by the larger surface (opened measuring chamber) on the right.

Thus the right-hand measuring chamber is closed, and the left-hand chamber opened. The surface on the left is now greater-causing motion in the opposite direction. This cycle is repeated with continuous flow at a rate proportional to the flow rate 1...230 cycles/s.

A volume of approximately 0.01 cm3 is displaced per pass. The built-in carrier frequency transducer senses the oscillating motion of the piston pendulum and pendulum arm without contact through the case, and outputs a digital signal with a frequency proportional to the volumetric flow.

Due to the negligible pendulum mass and minimum friction loss, the LFM detects minimum volumetric flow rates. Leakage loss is minimised by the piston design, which also provides good linearity and repeatability.

Kobold LFM Specifications

• Linearity: ±2.5% of reading
• Repeatability: ±0.1%
• Viscosity range: 0.6...6 mm2/s
• K factor: approx. 75000 pulses/l
• Material:
  Sensor housing: stainless steel 1.4435
  Pendular: stainless steel 1.4122
  Seal: PTFE, FKM, FFKM
• Connection:
  G⅛ female thread (output)
  6 mm Swagelok (input), NPT thread on request
• Filter: 40 μm; filter with 2 x 6 mm, Swagelok
• Max. pressure: 100 bar
• Max. Δp: 300 mbar at 5 cSt/0,25 l/min
• Max. temperature: -40°C...+80°C
• Electrical data:
  Push-Pull
  Umax = 30 V
• Electrical connection: 5-pin M12
• Installation position: vertical, flow rate from bottom to top
• Weight (with transducer): approx. 650 g
• Protection: IP 65

Typical Applications

• Additives
• Pharmaceuticals (good cleaning properties)
• Odorants/perfume
• Mains water and demineralised water
• Liquiefied gases
• Food

Download Datasheet: Kobold LFM Dual-Ring Piston-Pendulum-Flowmeter Low Volume

Reference : kobold.com