Products

Markets

Service & Support

Contact us

EN

My Bronkhorst

Products

Markets

Service & Support

Contact us

EN

My Bronkhorst

Products

Markets

Service & Support

Contact us

EN

My Bronkhorst

Bronkhorst gas flow meters

Gas Flow

Bronkhorst liquid flow meters

Liquid Flow

Bronkhorst pressure solutions

Pressure

Bronkhorst CEM vapor solutions

Vapor Flow

Bronkhorst accessories

Accessories

Bronkhorst software

Software

Customized flow solutions

Flow solutions

Life sciences

Life sciences

Chemical

Chemical

Energy transition

Energy transition

Food & Beverage

Food & Beverage

Surface treatment

Surface treatment

Analytical

Analytical

wafer foup

Semiconductor

Automotive

Automotive

Download files

Downloads

FAQ

FAQ

Global service

Global service

Fluidat

Fluidat

Service returns with RMA

Service returns (RMA)

Contact us

EN

My Bronkhorst

Get in contact

Online store

Gas Flow
Liquid Flow
Pressure
Vapor Flow
Accessories
Software
Flow solutions
Thermal instruments
Coriolis instruments
Ultrasonic instruments
Mass flow meter
Mass flow controller
Life sciences
Chemical
Energy transition
Food & Beverage
Analytical
Surface Treatment
Semiconductor
Automotive
Downloads
FAQ
Expert assistance
Calibration
Global service
Local service offices
Fluidat
RMA
Remote support
Knowledge base
Training
Contact
About us
News & Events
Careers

By category

Gas Flow
Liquid Flow
Pressure
Vapor Flow
Accessories
Software
Flow solutions

By Measuring principle

Thermal instruments
Coriolis instruments
Ultrasonic instruments
Mass flow meter
Mass flow controller

Online store

Life sciences
Chemical
Energy transition
Food & Beverage
Analytical
Surface Treatment
Semiconductor
Automotive
Downloads
FAQ
Expert assistance
Calibration
Global service
Local service offices
Fluidat
RMA
Remote support
Knowledge base
Training
Contact
About us
News & Events
Careers
EN
By category

Gas Flow

Liquid Flow

Pressure

Vapor Flow

Accessories

Software

Flow solutions

By Measuring principle

Thermal instruments

Coriolis instruments

Ultrasonic instruments

Mass flow meter

Mass flow controller

Online store
Life sciences
Chemical
Energy transition
Food & Beverage
Analytical
Surface Treatment
Semiconductor
Automotive
Downloads
FAQ
Expert assistance
Calibration
Global service
Local service offices
Fluidat
RMA
Remote support
Knowledge base
Training
Contact
About us
News & Events
Careers
Get in contact

Change Language

English

Current selection

Deutsch

Français

日本語

한국어

Nederlands

繁體中文

FAQ

Your question might have already been answered before. Below we have listed the most frequently asked question and provided them with explanation. If your question has not been answered yet feel free to ask us!

Get in touch : Single Column Link Button

Mechanical

Which cavity does my instrument have?

Where do IP Rating and NEMA Rating stand for?

What materials are the ‘wetted parts’ of Bronkhorst’s instruments made of?

Which sealing material is best for my application?

Which tube fittings does Bronkhorst recommend for my instrument?

Can my instrument be installed in any position?

How clean does my gas need to be?

Software & interfaces

How to connect FLOW-BUS fieldbus communication with Bronkhorst FlowSuite software?

Which gas data is embedded in mass flow meters/controllers with FLUIDAT on board?

Calibration

How to interpret the data and terminology on Bronkhorst calibration certificates?

How often should I perform a calibration check on my flowmeters/controllers?

Can I repair, clean and calibrate the instruments myself?

What does adjustment mean?

What is the meaning of As-found & As-left calibration?

Are all instruments factory calibrated?

Flow theory

What is the difference between volume flow and mass flow?

How do I calculate conversion factors, Kv-values and differential pressures?

Instruments

What are the benefits of a P-800 PPC (Process Pressure Controller) compared to conventional solutions?

Is it possible to modify my Mass Flow Meter into a Mass Flow Controller?

Which certificates and approvals are applicable for my instrument?

Close

Which cavity does my instrument have?

You can find the cavity of your flow or pressure meter/controller in the table below:

Series Cavity
EL-FLOW Base BSPP RS-type based cavity
EL-FLOW Prestige BSPP RS-type based cavity
EL-FLOW Select BSPP RS-type based cavity
LOW-dP-FLOW BSPP RS-type based cavity
EL-PRESS BSPP RS-type based cavity
EX-FLOW BSPP RS-type based cavity
IN-FLOW BSPP RS-type based cavity
IN-PRESS BSPP RS-type based cavity
LIQUI-FLOW BSPP RS-type based cavity
MASS-STREAM D-6300 BSPP RP-type based cavity
MASS-STREAM D-6400 BSPP ISO 1179-1 based cavity
MASS-VIEW BSPP ISO 1179-1 based cavity
FLEXI-FLOW BSPP ISO 1179-1 based cavity
IQ+FLOW 10-32 UNF class 2B cavity
EL-FLOW Metal no cavity - welded or part of body
EL-PRESS Metal no cavity - welded or part of body
ES-FLOW no cavity - welded or part of body
µ-FLOW no cavity - welded or part of body
(mini) CORI-FLOW no cavity - welded or part of body
IN-FLOW/EX-FLOW F-107/117 no cavity - welded or part of body
IN-FLOW/EX-FLOW F-106 no cavity - wafer type

RP-RS Based Cavity

Close

Where do IP Rating and NEMA Rating stand for?

IP Rating 
The IP Rating (Ingress Protection Rating) of an instrument consists of the letters IP followed by two digits and an optional letter. As defined in international standard IEC 60529, it classifies the degrees of protection provided against the intrusion of solid objects including body parts like hands and fingers, dust, and accidental contact (the first digit after IP), and water (the second digit after IP) in electrical enclosures. 

NEMA Rating 
The National Electrical Manufacturers Association (NEMA) in the United States also publishes protection ratings for enclosures similar to the IP rating system published by the International Electrotechnical Commission (IEC). NEMA however also dictates other product features not addressed by IP codes, such as corrosion resistance, gasket aging, and construction practices. 

IP vs NEMA Rating
IP and NEMA Rating share a similar purpose, protecting electrical equipment against harmful environmental impacts. However, it is not possible to convert an IP rating to a NEMA type rating or vice-versa.

Close

What materials are the ‘wetted parts’ of Bronkhorst’s instruments made of?

The standard material of construction for all instruments is stainless steel 316 or equivalent. Our product series MASS-STREAM, FLEXI-FLOW and IQ+FLOW can also be offered with aluminum body material. On request some wetted parts are available in monel ® or hastelloy ®. Contact factory for more information. 

Standard seals are Viton® (FKM) for a thermal gas mass flow meter / controller and Kalrez® (FFKM) for a thermal liquid mass flow meter / controller. (mini) CORI-FLOW Coriolis mass flow meters are metal sealed. Controllers contain internal seals of Viton® (FKM) (factory standard), EPDM or Kalrez® (FFKM). 

Close

Which sealing material is best for my application?

The selection of elastomeric seals for our instruments must be based on chemical resistance at operating conditions. Bronkhorst has gathered a lot of information about the compatibility of various compounds, and we can advise our customers accordingly. However, our recommendations must be considered as guidelines for which no guarantees can be given. 

If you are looking for a specific answer to your application, please feel free to contact us.

Close

Which tube fittings does Bronkhorst recommend for my instrument?

As a standard, we use compression type connections or face seal (VCR/VCO) fittings with BSPP thread on our instruments. 

BSPP (British Standard Pipe Parallel) is, as the name suggests, a parallel fitting. The threads are used to hold the two pieces together and not to create a seal. The sealing is done by an elastomeric seal external to the thread. Because the seal is external to the thread there is no danger of debris in the threads being forced into the flow path of the gas. For this reason, we do not recommend NPT fittings with PTFE (Teflon) tape sealing. 

Close

Can my instrument be installed in any position?

Summary of the video:

  • All gas flow meters/controllers should be mounted horizontally at pressures higher than 10 bar.
  • Below 10 bar, gas flow instruments may be mounted in vertical position with one exception: LOW-dP-FLOW instruments must always be mounted horizontally. 
  • Liquid flow instruments may be mounted either horizontally or vertically. However, a few considerations should be made. Please consult the applicable instruction manual. You may also find it useful to read our e-book about this topic: E-book 'How to handle low liquid flows' | Bronkhorst 
Close

How clean does my gas need to be?

Summary of the video: 

Summary of the video:

Generally, it is always best to work with dry and clean gases. However, some instruments are less sensitive to contamination. Our LOW-dP-FLOW instruments have relatively large inside diameters but still depend on a consistent split between main channel and bypass-sensor. MASS-STREAM instruments do not have a bypass. Their main channel is easier to clean in case contamination affects your process.
Our liquid flow instruments are designed for smallest flow rates and therefore have small internal passages. For this reason, you should avoid blockage by particulates or gas bubbles.

Close

How to connect FLOW-BUS fieldbus communication with Bronkhorst FlowSuite software?

Bronkhorst instruments are equipped with a micro-controller for exchanging parameter value information with other instruments / devices connected to the same FLOW-BUS system and/or via RS232 to a PC.  
 
Like Modbus, FLOW-BUS is a line-topology serial communication protocol over RS485. Each instrument must be “daisy chained” one after another with begin and end resistors. 
 
Standard RJ45 Shielded (F)TP patch cable or M12 cable supplies the FLOW-BUS signal and 24 Vdc power. 
 
The PC's USB port connects via RS232 to the first device. We strongly recommend the use of special connectors for bus-begin and -end termination. 

Close

Which gas data is embedded in mass flow meters/controllers with FLUIDAT on board?

Density, viscosity, thermal conductivity and heat capacity of the processed media change under the influence of pressure and temperature. The FLUIDAT On Board algorithm continuously recalculates these properties and uses them to adjust the gas flow. 

  • EL-FLOW Prestige instruments embed the complete FLUIDAT database.
  • FLEXI-FLOW Compact comprises a built-in database with properties of 22 commonly used gases: 
    Acetylene (C2H2), Air, Allene (C3H4 #1), Argon (Ar), Carbon dioxide (CO2), Carbon monoxide (CO), Cyclopropane (C3H6 #1), Deuterium (D2 #1), Ethane (C2H6), Ethylene (C2H4), Helium (He), Hydrogen (H2), Krypton (Kr), Methane (CH4), Neon (Ne), Nitrogen (N2), Nitrous oxide (N2O), Oxygen (O2), Perfluoropropane (C3F8), Propane (C3H8), Propylene (C3H6 #2), Propyne C3H4 #2
  • MASS-STREAM D-6400 instruments have on-board data of the following 36 gases: 
    Air, Ammonia (NH3), Argon (Ar), Carbon dioxide (CO2), Carbon monoxide (CO), Chlorine (Cl2), Dimethyl ether (C2H6O #1), Hydrogen Chloride (HCl), Hydrogen Sulfide (H2S), Methanethiol (CH4S), Nitrogen (N2), Nitrogen oxide (NO), Nitrous oxide (N2O), Oxygen (O2), Ozone (O3), Pentanethiol (C5H12S), Silane (SiH4), Sulfur dioxide (SO2) and 16 types of hydrocarbons 
Close

How to interpret the data and terminology on Bronkhorst calibration certificates?

By clicking the link below you can open a sample certificate with the explanation of the different fields in calibration certificates. 

Close

How often should I perform a calibration check on my flowmeters/controllers?

Flow meters, flow controllers, in fact all process instruments, experience wear from the conditions of the process in which they are installed. Temperature, electronic component tolerance shift, contamination build up over time (even very slight), plus other factors will all contribute to affecting the accuracy of an instrument. Your instruments should regularly undergo, at a minimum, a calibration check if not a recalibration. But how often? 

Because the nature of each application is different (conditions, running time, etc.) a calibration can last three years or three months. Bronkhorst instruments do not have specified due dates for calibration. We suggest that our instruments be calibrated every year. However, based on the application conditions, and perhaps company quality procedures, each customer must determine when they need to send in an instrument for recalibration. Properly calibrated instruments will be more accurate, more reliable, help ensure consistency, and help improve production yields. 

An on-site calibration check may be considered to reduce downtime and costs. For this purpose, Bronkhorst offers their easy-to-use FLUICAL Portable Calibrators. 

Close

Can I repair, clean and calibrate the instruments myself?

Calibration

It is possible to calibrate an instrument by checking its measured value with an accurate reference yourself.  

 

Repair and cleaning 

It is possible to restore the function of the instruments if no parts are irreversibly damaged. However, it can affect the accuracy of the device. If the device has been opened, the calibration as well as the pressure and leakage test carried out at the factory is no longer valid. Bronkhorst cannot accept any warranty for any instruments opened by other than Bronkhorst certified service offices.  

In general, we recommend returning contaminated or defective devices to our Bronkhorst certified service offices for repair, cleaning and calibration services. 

Close

What does adjustment mean?

By adjustment of the measuring signal, we mean that we can change the settings of the meter according to the values of the used reference device. This is to eliminate systematic measurement deviations.  

Adjustment is important when the output of the measuring device is not only expected to be repeatable but also indicates the true value. Instead of adjusting a measuring device, the end user can also take the deviation which is stated on the calibration certificate to make an adjustment in the computer. 

Close

What is the meaning of As-found & As-left calibration?

As-found calibration

An as-found calibration is a calibration prior to repair or adjustment. This is often referred to when a flow meter has been sent back to the service office and it states the condition in which it is received.  

 

As-left calibration

An as-left calibration is a calibration after repair or adjustment. It provides validation for repairs or adjustments. 

 

Calibration As Found As Left

Close

Are all instruments factory calibrated?

All instruments in our product portfolio undergo factory calibration and are traceable to national standards. They are delivered with a (digital) calibration certificate.  

Additionally, as an option, you can choose an ISO/IEC 17025 calibration from our accredited Bronkhorst Calibration Center instead of the factory calibration. For customer specials or OEM products, calibration is part of the agreements made with the customers. 

Read more about ISO/IEC 17025 calibrations

Close

What is the difference between volume flow and mass flow?

A mass flow rate should be expressed in units of mass such as g/h, mg/s, etc. Most users, however, think and work in units of volume. That’s fine, and to use density in converting mass flow to volume flow, we must pick a set of specific pressure and temperature conditions at which we use the density value for the gas. Worldwide, there are quite a lot of these standard reference conditions for conversion.  
 
The following reference conditions are used by Bronkhorst: 

  • When the mass flow rate is expressed with subscript n as in mln/min or m3n/h. Subscript n represents (European) normal operating conditions, which means that a fluid density at a temperature of 0 °C and a pressure of 1 atm (1013 mbar) are selected for conversion from mass flow rate to volumetric flow rate. 
  • As an alternative, a temperature of 20°C and a pressure of 1 atm (1013 mbar) are used to refer to (European) standard reference conditions, indicated by the subscript s in the volumetric units (mls/min, m3s/h). These values resemble average temperature and pressure conditions at sea level. 
      

Keep in mind: 
Please be aware of these differences, because mixing up these reference conditions for gas flows (especially the temperature difference between 0 and 20°C) may lead to an error of 7 %! 

Close

How do I calculate conversion factors, Kv-values and differential pressures?

Bronkhorst developed a unique database, consisting of fluid data of over 1800 fluids. Using application software routines various calculations can be made on-line at our internet site www.fluidat.com.

We invite our customers to visit this site for free registration. Upon receipt of your login details you will be able to calculate conversion factors/tables for Bronkhorst thermal gas & liquids flow meters, calculate Kv-values and orifice sizes for Bronkhorst control valves, calculate the pressure drop across Coriolis flow meters and in-line filters and perform calculations relevant to our CEM evaporation system. 

Close

What are the benefits of a P-800 PPC (Process Pressure Controller) compared to conventional solutions?

Benefits of a Process Pressure Controller versus a valve? 

For precise control of the pressure in a process chamber, or to control the pressure in your system, electronic (digital) pressure controllers are used. Such a pressure controller regulates a control valve, allowing to increase the pressure inside the process chamber. To relieve the pressure, traditionally bleed valves are used, continuously venting to the environment. 

In case of expensive or dangerous process gases this is not preferred. In that case, often an additional valve with valve steering unit is used to control the relief. These additional components make the system complex.  

The P-800 Process Pressure Controller series has an integrated relief valve, reducing the components and avoiding continuous venting to the environment. 

Check out the benefits of the P-800 Process Pressure Controller compared to a conventional solution using a bleed valve and a solution with a separate relief valve: 

Solution with Bronkhorst Process Pressure Controller

Pro's: 

  1. Low gas consumption
  2. Safe solution for any type of gas
  3. Compact integrated solution
  4. Economical "plug-and-perform" solution

Conventional Solution with Bleed to Atmosphere

Contra's:

  1. Higher gas consumption due to constant bleed
  2. Not suitable for dangerous gases

 

Conventional Solution with Separate Relief Valve

Contra's:

  1. Connection of various components requires more space
  2. Purchase, mounting and test of various components is less efficient and more expensive

 

Close

Is it possible to modify my Mass Flow Meter into a Mass Flow Controller?

Yes, it is possible to modify a Mass Flow Meter (MFM) into a Mass Flow Controller (MFC), but it involves several technical considerations and modifications. Bronkhorst flow meters are generally equipped with control electronics, including a PID controller, to adjust the valve position and maintain the desired flow rate. An additional control valve can be mechanically close-coupled to the flow meter, e.g., by using a port connector. The electric interconnection of the valve cable requires an electronics housing suitable for the entry of the valve cable. 

 
Some considerations: 

  • Upon assembly, the control settings (PID controller) must be adjusted for the application. 
  • The cabling and power supply must match the flow meter and valve combination. 
  • Modifying an MFM into an MFC requires a good understanding of fluid dynamics, control systems, and electronics. Modifying an MFM to an MFC is reserved for your local Bronkhorst channel partner. Please feel free to contact him to discuss the possibilities.
Close

Which certificates and approvals are applicable for my instrument?

Apart from the calibration certificate provided for any measuring or control device, your Bronkhorst instrument complies with the European (CE) legislation. These are the certificates specified below as 'standard'. 

Depending on the product series, optional approvals are available. 

Click on the product name below for more detailed information. 

● = standard certificate 

o = optional certificate 

certificates-bronkhorst-flow-instruments

Bronkhorst
  • Tel: +31 (0)573 45 88 00

  • [email protected]

Control Management Technology (CMT)

333 Troy Circle, Suite X

TN 37919 Knoxville

(865) 584-0208

[email protected]

View nearby offices
Get in touch
  • Local sales partners

  • Ask a question

  • Get a quote

  • Emergency number

Go directly to
  • Downloads

  • Global service

  • Careers

  • Impressum

Social
  • LinkedIn

  • YouTube

Newsletter

Subscribe to our mailing list and receive regularly an update.

Subscribe : tertiary button

Copyright © 2026 Bronkhorst. All rights reserved.

Terms & Conditions

Disclaimer

Privacy statement