We offer the widest product range of low-flow (mass) flow meters and controllers on the market. Numerous styles of both standard and bespoke instruments can be offered for applications in laboratory, machinery, industry and hazardous areas.
Customer satisfaction, innovation and quality of product and service have been the cornerstones of Bronkhorst's success. Based on our experience, innovation and sense of responsibility, a relationship with Bronkhorst assures Performance for Life.
Bronkhorst instruments are used for numerous applications in many different markets. In this section you will find an overview of the main markets for our equipment, illustrated with some typical examples of applications.
Are you looking for technical documentation, are you interested to learn more about the measuring principles of Bronkhorst products, or you do want to get in contact with a Bronkhorst Service Engineer? This section will guide you to the relevant service & support topics.
Bronkhorst High-Tech BV the leaders in Mass Flow Meter / Mass Flow Controller technology for gases and liquids, Pressure Controllers and Evaporation Systems.
The ranges of Bronkhorst's thermal mass flow meters / controllers for gases are specified in such units as ln/min, sccm or m3n/h. These units look like volumetric units, but in truth they are expressions of Mass Flow. What is the story behind this?
Imagine you have a cylinder of 1 litre, which is closed by means of a moveable piston of negligible weight. This cylinder contains 1 litre of air at ambient pressure, approx. 1 bar. The weight of this volume of air at 0°C is 1.293 g, this is the mass. volume flow vs mass flow
When we move the piston half way to the bottom of the cylinder, then the contained volume of air is only ½ litre, the pressure is approx. 2 bar, but the mass is unchanged, 1.293 g; nothing has been added, or left out.
Following this example, mass flow should actually be expressed in units of weight such as g/h, mg/s, etc. Most users, however, think and work in units of volume. No problem, provided conditions are agreed upon, under which the mass is converted to volume. Following the 'European' definition, a temperature of 0°C and a pressure of 1,013 bar are selected as "normal" reference conditions, indicated by the underlying letter "n" in the unit of volume used (mln/min, m3n/h). Alternative, a temperature of 20°C and a pressure of 1,013 bar are used to refer to "standard" reference conditions, indicated by the underlying letter "s" in the unit of volume used (mls/min, m3s/h). Please be aware of this, because if the difference is not considered, it may lead to an error of 7%!
According to the 'American' definition the prefix "s" in sccm, slm or scfh refers to "standard" conditions 101.325 kPa absolute (14.6959 psia) and temperature of 0°C (32°F).
Volumetric measuring devices, like variable area meters or turbine flow meters, are unable to distinguish temperature or pressure changes. Mass flow measurement would require additional sensors for these parameters and a flow computer to compensate for the variations in these process conditions. Thermal mass flow meters are virtually insensitive to variations in temperature or pressure.
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