Micro Flow Meter (LFM)

Micro Flow Meter (LFM)

Micro Flow Meter is suitable for low-viscosity fluids in dosing and filling applications of all kinds. Its measuring element is based on the principle of a double ring piston meter. Thanks to the low pendulum mass and minimal frictional losses, the LFM responds to even the smallest volume flows. Only high-grade stainless steel that even withstands corrosive media is used in the production of the micro-flowmeter.

The high-precision measuring element and extremely tight production tolerances of the single components minimize leakage and thereby guarantee good linearity and reproducibility of the LFM.

Micro Flow Meter Application

The flow meter LFM is designed for low-viscosity fluids of all types, especially for use in dosing and filling devices. It is designed for low volume flows from 0.005 l/min. and shall be applied wherever small amounts of additives are dosed or injected.

Due to having large resolution it is guaranteed optimal dosing accuracy even in case of the smallest liquid volumes. The values of self-pulsing flows are reproducible with the repeated accuracy of +/- 0.1%. Due to its small compact design the LFM may be used without problems even in a very confined space for installation.

Application :

• Additives
• Pharmaceuticals
• Aromatic substances/perfumes
• Tap-water and demineralized water
• Liquefied gases
• Fluid food
• 2- and 3-component-applications
  
  

Micro Flow Meter Technical Data

• Measuring Range : 0.005 up to 0.25 l/min.
• Viscosity : 0.6 up to 6 mm²/s.
• Linearity : ±2.5 % of actual flow.
• Materials :
  • Housing : as per DIN 1.4435 [AISI 316 L].
  • Pendulum : as per DIN 1.4122.
  • Ring Piston : as per DIN 1.4122.
  • Seals : PTFE, FFKM, FKM.
• Pressure : max. 100 bar [1,450 psi].
• Medium Temperature : -20 °C up to +120 °C [-4 °F up to +248 °F].
  
  

Pickups and Amplifiers

• Carrier-Frequency Pulse Amplifier with Single Pickup (VTE 02).
• Carrier-Frequency Pulse Amplifier with Single Pickup (VTE 04)
• Local Converter with Interface (WT.02/WI.02).
• Carrier-Frequency Pulse Amplifier (VTE Ex).
  
  

Evaluation Electronics

• Local Display with Analog and Frequency Output (VTC/VIC).
• Local Display for wall mount with analog and frequency output (VTG/VIG).
• Local Display battery-powered (VTB).
• Panel Mount Displays with Analog and Frequency Output (FAS 100).
• Wall Mount Displays with Analog and Frequency Output (FAW 100).
• Frequency to Analog Converter (FAU 50).
• Intrinsically Safe Supply Unit (EWS).
  
  

Principle and Design

The measuring device consists of a double ring swinging piston which produces oscillating rotary and swinging motion due to alternating filling and emptying the measuring chambers.

Thanks to a small weight of the pendulum and the minimum losses arising from friction the flow meter LFM reacts even to the smallest volume flows. At a constant flow, the cycle described above is repeated proportionally to the flow approx. 5 to 300 times per one second. In the process, for each one cyclic revolution a volume of approx. 0.01 cm³ is pressed out and thereby one pulse. In addition, the piston design minimizes losses due to leakage and this guarantees good linearity and repeatability of the measured values.

A suitable frequency-and pickup system records oscillation motions in a contactless manner through the body wall and transmits output signals at a frequency which is proportional to the volumetric flow.

The flow meter LFM 10 is compact and its weight, including the integrated sensor (VTE-CM-S) is only 650 g. This flow meter is made of stainless steel, like other KEM flow meters. In order to achieve a faultless operation it is recommended to equip the flow meter LFM with a filter of aperture size < 40µm.