Digital Liquid Mass Flow Meters / Controllers LF-F/LV-F series

Overview

The LF-F/LV-F Series are digital liquid mass flow controller using a Peltier element which cools the liquid rather than the more common thermal heating element. This gives the advantage of removing the risk of boiling those chemicals that have a low boiling point, thus allowing a greater range of chemical control.

Features

  • Offer micro-litre to ultra low flow rate control.
  • Enable precision flow control of low boiling point and high viscosity liquids.
  • Ultra clean.

Manufactured by HORIBA STEC

Measurement Techniques

Cooling measurement method
The flow rate sensor in the LF-F/LV-F series of fine mass flow controllers for liquids consists of an electronic cooling element (Peltier element) that is in contact with a capillary tube, as well as several temperature detection elements. When the liquid is flowing, the sensor detects the temperature rise  (ΔT) corresponding to the flow rate and displays it as flow rate. Unlike methods where heat is added, this cooling method enables flow rate measurement of liquids with low boiling points. It also prevents problems with interference due to the influence of secondary discharge (vaporization) and makes accurate flow rate measurements possible.

Structure/Operating principle
The LV-F series of mass flow controllers and LF-F series of mass flow meters use the same measurement principle. The LV-F also has a piezo actuator valve and an internal comparison control circuit. These compare the flow rate setting signal and the flow rate output signal and automatically control the valve aperture so that the two signals will match to control the liquid. Since they use a feedback control system, there are no flow rate variations as a result of external factors, and, there fore, stable, accurate control is possible. The use of piezo actuator valve, which is both stable and does not generate heat, as the control valve makes these units ideal for flow control of liquids with low boiling points.

Accessories


PE-D10-20
The PE-D20 control unit integrates high frequency functions via the front panel controls.
PE-D10-20
The PE-D10 is a standalone unit for use with mass flow meters.
PE-series
The PE series of dedicated power sources can be used as drive power sources for mass flow controllers, meters, and auto pressure regulator as well as for dedicated display units, and supply the standard flow rate setting voltage. The series includes a lineup of models that have flow rate alarm output function, models offering 0 signals and 4 to 20mA, and models that are capable of driving up to six units.
Display unit DU series
The DU-102E and DU-103K display the flow rate output signal from mass flow controllers and meters. Matching these units to the full-scale flow rate values of mass flow controllers and meters enables direct monitoring of control and measured flow rates.