... measure the air and gas flow fast and precisely. They are available in many different sizes and are the right choice for many applications in flow measurement and calibration with air or gases.

At many applications a LFE can satisfy a flow span, for which normally 2 different venturis, nozzles or orifices were needed. The accuracy at the lower end of the range will be limited only by the flow stability and by the evaluation of the differential pressure signal .

• LFE - how does it work?
• LFE - advantages
• Choice of LFE standard models
• Choice of LFE for special applications
• Worksheets about LFEs
• Controller S320 standard software LMF

... were sized and manufactured according to the international standard DIN EN ISO 5167. Orifices are pressure drop devices for the measurement of the average flow velocity and volume flow and were operated in subcritical conditions.

Orifices are precisely manufactured drillings with defined tolerances dependand on the application. They have sharp edges to guarantee precise geometric accuracy. The measures of the drilling of the orifices are engraved on the tag for clear identification. The disks have a thickness of 3 to 10 mm and the wall thickness of nozzles depending mainly on the application pressure. They are made of 304, 316 or special steel to grant a high temperature proofness.

Venturi Nozzles at Sonic Flow
according DIN EN ISO 9300.

For the flow measurement of air but also of pure gases sonic nozzles at critical pressure (sonic flow) conditions according to the standard DIN EN ISO 9300 are an ideal pretty long time stable transfer standard.
Nozzles in the flow range of 15 l/h up to aproximatly 2000m³/h, nozzle sections and galleries in a diameter range from DN 25 to DN 200 we can realize according to the standard. In equivalence to the standard we can manufacture bigger and smaller nozzles also.
Simple handling, fast response time, high measurement accuracy and control of the flow (between 0,12 % o.R. and 0,3 % o.R.), and a very high long time stability and accordingly long recalibration periods ( up to 2 m³/h = 5 years and above = 10 years) are unbeatable properties for repeating calibration tasks for volume flow measurement devices for air and gases.

Accutube Flow Sensors:

The averaging Accutubetube is a pressure drop device, on wich the flow of the flowing medium causes a differential pressure, which is proportional to the flow speed. It works similarily like an orifice or a venturi-nozzle and other so called squareroot-devices.

Characteristics:

• Double "D"-chamber construction
• Bidirectional measuring device
• Simple installation and maintenance
• Easy upgrade of elder systems

Gas Meters measure the flow with the principle of volume displacement. They are a physical primary standard for volume. Depending on the measurment range of flow their are different constructions such as gas clock, positive displacement and turbine meter available. In all of them a certain number of pulses per round are proportinal to the flow.