Thermal mass flow regulators and mass flowmeters for gases are now among the standard instruments used in industrial laboratory and production processes: these units measure the mass flow directly.

Thermal mass flow regulators and mass flowmeters for gases are now among the standard instruments used in industrial laboratory and production processes. Because these devices measure the mass flow directly, without diversions in the form of measuring the flow speed or the volume, the measurement results can be transferred without elaborate conversions to reaction equations and formulations. The special feature about the Smart-Trak generation of devices from Litre Meter, the flow measurement specialists, is that one and same device can be used for ten different gases, and without any shortfall in precision needing to be taken into account.

With the Dial-a-Gas function and the user-friendly interface for the pilot module, the operator can adjust the device on the spot for use with different gases, and even select other operating parameters.

The devices are calibrated in advance to the ten gases, the most commonly used gases in industrial sectors and laboratories in the fields of biotechnology and pharmaceuticals, as well as in the analysis and research sectors as well.

If required, a device can also be calibrated to a special gas, as a departure from the ten standard gases, on the basis of the type of application.

The Dial-a-Gas function can be selected either by means of the pilot module, available as an accessory, or with the aid of a PC by means of the computer interface.

The incorporation of the Smart-Trak mass flowmeter in automatic systems and control circuits is extremely simple by means of the various different input and output signals available.

Suitable for both remote monitoring purposes as well as use as integrated components in analysers and systems, Smart-Trak offers digital and analogue inputs and outputs without the need for elaborate cabling.

An RS232 interface is available, as well as two analogue outputs.

While it used to be necessary to have considerably expensive supply power units with +/- 15 VDC outputs, these modern gas mass flow regulators are designed for supply voltages of 24 VDC.

In the basic design, the regulator or flowmeter is available either with the directly-integrated electronics or with remote electronics units, which offers some major advantages with regard to the installation dimensions.

The pilot module, which is available as an accessory, a display and operating unit, is supplied either secured directly to the device electronics, or can be installed by the operator up to 15 metres away from the device.

This means that the very small and compact module can now replace the external control modules, which used to be required.

For systems in which standard devices are required, the use of units without pilot modules is a good solution.

The adjustment and setting of the parameters is carried out either directly at the factory, or the device parameters can be programmed by the operator/system constructor, by means of a PC, depending on its use.

The small structural dimensions of 25 x 75 x 125 mm also allow the operator to use the Smart-Trak as a direct replacement device for other makes.

The Smart-Trak regulating valve balances out relatively large fluctuations in operating pressure and temperature.

The operator can select between operating modes, such as valve closed, normal, and flush, via the pilot module or the interface.

As well as that, the response behaviour for the different requirements and systems pressures can also be adjusted.

The device bodies, manufactured entirely out of stainless steel, are available for measuring ranges between 0 and 10 Ncm3/min and 0 to 50 NI/min.

Other construction sizes for higher pressure flows are in preparation.

These devices can be used for all clean gases, as well as corrosive and toxic ones.

Use in Fermenters and Bioreactors.

A typical area of use for mass flow regulators is the fermenter sector.

The function of these bioreactors can be optimised by the use of thermal mass flow regulators.

In fermenters, bacteria (cell cultures) are cultivated for the most widely-differing areas of application.

To achieve this, they are placed in nutrient solutions with the admixture of the most suitable possible gas atmosphere, favourable for the proliferation of the cell cultures.

The ideal gas atmosphere is composed of the exact mixture of oxygen, carbon dioxide, and air.

The supply of this gas mixture is ensured by the use of mass flow regulators.

The exact gas mixture in this case ensures optimum growth and growth rates, making use of cell mutations or even the death of cell cultures.

The reference values for the devices are specified by a super-ordinated computer, and the mixing ratio is changed in accordance with the progress of the process.

A further automation step in such processes for the monitoring and adjustment of the optimum gas mixture is the parallel monitoring of the pH value and of the proportion of oxygen in the solution.

The super-ordinated computer takes these measured values as the basis for calculating the correct gas mixture, and passes the corresponding reference values directly to the mass flow regulator.

The Smart-Trak is particularly interesting for the manufacturers of systems such as these.

Because the devices can be used for ten different gases, fewer different types and designs are needed.

The possibility of direct exchange of the devices between one other, as well as of replacing devices from other manufacturers, reduces the need to keep these items in storage.

Thanks to the small surface area of the regulators, there is no problem in using them to replace other devices, and no need either for major modifications to be made to the systems.

The manufacturers of the measuring devices are themselves in a position to produce devices from stock, and can so supply them more quickly, something that was not possible previously because of the wide range of types needed in order to adjust calibration to a specific gas.

Because the operator can also adjust the measurement range with the Smart-Trak within the specified limits himself, keeping items in store and obtaining stocks has also been made much easier.

Applications in the Pharmaceutical Industry.

Another typical situation for the use of mass flowmeters is the screening of tanks and other containers in which reactive fluids are being held or processed.

Most organic fluids and oils react with the oxygen in the air and change their properties and characteristics as a result.

The standard solution for this problem is to screen the product with nitrogen.

To do this, the tank chamber is filled with nitrogen above the fluid, and a certain volume is constantly conducted through the upper part of the tank in order to ensure that any contact between the product and the oxygen in the air is avoided.

In many cases, it is entirely sufficient simply to monitor the pressure, but the use of flowmeters offers a number of advantages, such as the measurement and totalling of the volume of nitrogen consumed.

With the use of two devices to monitor the inflow and outflow of nitrogen, leaks can be readily identified.

The nitrogen inflow can be specifically adjusted and regulated respectively, if more or less of the product is to be drawn off from the tank.

In the manufacture of glass ampoules and other glass containers for pharmaceutical and medical products, the gas mixture of the burner flames, composed of natural gas and air, needs to be monitored very precisely.

Automatic adjustment and regulating by means of thermal mass flow regulators leads to a substantial reduction in the wastage rate, as well as providing other advantages.

The regulating of very small mass flow volumes of less than 50 NI/h, with fluctuating upstream or downstream pressures, can be achieved with no problem at all.

The enrichment of the combustion air with oxygen improves the combustion quality of natural gas and increases productivity on the manufacturing lines.

Bronkhorst, the gas mass flow controller specialists, will have their stand within the 'Practical Vacuum' Exhibition, alongside MTEC this year: visit us there to get an invitation to UK Open Days.

Bronkhorst, the gas mass flow controller specialists, will have their stand within the 'Practical Vacuum' Exhibition, located alongside MTEC this year. Many of the major gas flow control customers using Bronkhorst equipment are involved in vacuum technology, or controlled atmosphere processes, so their instrumentation will be on show alongside many of their OEM customers and users. Bronkhorst EL-FLOW thermal mass flow measurement systems and controllers for gases will be on show, plus also the EL-PRESS pressure controller units.

Bronkhorst products similar to these used for gas flow are also applicable to liquid mass flow, for either control or measurement.

So there will be products on display of interest to all engineers with accurate liquid and gas dosing and flow control requirements.

The Cori-Flow Coriolis based mass flowmeter and controller will be on display, alongside the LIQUI-FLOW mass flow controlled pump and pulsation free measured liquid dosing system.

During May 2004, Bronkhorst will be having three 'Open days' at their Cambridge UK sales and service headquarters, for customers to visit and see the flow calibration facilities, plus also see their full range of products actually under test and in operation.

Why not make a note to drop in on the Bronkhorst stand at Practical Vacuum, NEC Hall 11, on 11-12 February, and register for an invitation!

Proven in a wide variety of gas flow applications, the Endress+Hauser t-mass thermal mass flowmeter is the perfect solution for compressed air, biogas and other utility gas applications.

The rising cost of gases and their wide use in industry has meant that accurate measurement of gas flow has become increasingly important to efficient plant operation and environmental protection. Proven in a wide variety of gas flow applications, the Endress+Hauser t-mass thermal mass flowmeter is the perfect solution for compressed air, biogas and other utility gas applications. With excellent turndown (100:1) and negligible pressure loss, it is ideal for low flows or determining background leakage rates.

This is particularly important in compressed air applications, as energy consumption is reduced and money saved by addressing leakage problems.

What's more, t-mass can be supplied to suit a wide range of pipe sizes and connections and is ATEX certified for hazardous area use to suit all areas of industry.

* Compressed air generation and distribution.

* Biogas.

* Oxygen and nitrogen metering.

* aeration air.

With on-board diagnostics and HART communication, t-mass is simple to maintain and offers a low cost of ownership.

Supplied with a display and pushbutton programming as standard, it is user-friendly and can be commissioned in the field with minimum fuss.

The Sierra fast response in-line Series 730 Accu-Mass flow meter has been introduced by Litre Meter, with full CE-approval: with a very small footprint, the unit is well suited for OEM applications.

Litre Meter introduces the Sierra Instruments improved Series 730 Accu-Mass flow meter with CE-approval. With a very small footprint (6.4' x 1.1' with a 3.1' to 5' F/B), the in-line mass flow meter is well suited for OEM applications. The fast-response (200 ms) flow meter measures flow rates of non-corrosive gases, including methane gas, in ranges from.5 to 50 SCFM, and delivers a linear output signal proportional to total gas mass flow rate.

This direct mass flow monitoring method eliminates the need for separate temperature and pressure inputs, improves measurement accuracy, and helps to reduce system cost.

The Series 730 provides +/-1% of full-scale accuracy, and +/-0.2% of full-scale repeatability over a wide temperature and pressure range.

The CE-approved instrument is available in a water-resistant NEMA 2 enclosure, which can be mounted directly or remotely.

Input power requirements are 15 or 24 VDC, and output signal options include 0-5 VDC, 0-10 VDC, or 4-20 mA.

The Series 730 mass flow meter is distinguished by its exceptional low-flow sensitivity, negligible pressure drop, fast response, small footprint, and economical price.

The patented thermal sensor has demonstrated its reliability and accuracy in hundreds of thousands of applications, including laboratory devices, semiconductor equipment, biotech and pharmaceutical manufacturing equipment, and building automation systems.

PVL has an innovative solution for companies who want to have compressed air or other gas flowmeters permanently installed in multiple locations, but for whom the cost would be prohibitively high.

PVL has an innovative solution for companies who would like to have compressed air or other gas flowmeters permanently installed in multiple locations, but for whom the cost would be prohibitively high. The PVL alternative is a flowmeter that can be easily moved between any number of pipes, quickly and easily, with simple press-in, pull-out insertion and removal. Making this possible is a new design of manifold with a built-in ball valve.

When you want to move the flowmeter to a new location, you simply close the ball valve to stop the air flow, remove the probe, cap off the pipe, and then re-open the ball valve to restart the air flow - an operation that takes seconds.

Installing the flowmeter into a different pipe is just as easy.

The manifold has been designed so that the flowmeter probe auto-inserts to the correct depth and orientation.

The probe itself is a mass flow meter design, optimised for accuracy, and suitable for pipes from 1inch diameter up to 6inches diameter.

The innovative design is based on the successful PVL ClimaAir technology, and is available with a 4-20mA analogue output, a frequency output, or with a user-settable switched output.

Combining compact construction and easy installation with a robust design, the flowmeter is suitable for use with a wide range of gases including air, oxygen, nitrogen, helium, argon, carbon dioxide, hydrogen, nitrogen dioxide, carbon monoxide, and many different hydrocarbons.

This new technique is ideal for Monitoring compressed air consumption.

Judging by the number of enquiries received, many companies are still having difficulty in measuring the 'actual' flow rate of their compressed air system.

Referring to the manufacturers label on the compressor can often give very misleading information.

For example a CFM rating may only refer to the Free Air Delivery of the compressor, which in reality can differ a great deal from what is actually flowing though the system.

Why take the risk of fitting an expensive flowmeter when the output could be grossly inaccurate because the flowmeter is either too small or too big for the actual flow that is to be measured.

What is needed is an easy to use device to accurately measure the air flow by taking into account the pressure, the temperature, the air speed and the diameter of the pipe.

The ClimaAir Kit can be used just as simply as a voltmeter or ammeter.

Just plug it in and within seconds it will display m3/hr accurately.

Bronkhorst Hi-Tech announce ATEX approved gas flow meters and controllers for use in Zone 1 hazardous areas, or on flammable gases: a 50:1 range and 1% flow accuracy is on offer.

Bronkhorst Hi-Tech announce a range of ATEX approved gas flow meters and controllers for use in Zone 1 hazardous areas, or on flammable gases. First to achieve ATEX certification for the thermal mass flow measurement technique, the Bronkhorst Ex-Flow system has an intrinsically safe measurement head, and gives flow measurement accuracy of 1% over a 50:1 measuring range. Ex-Flow instruments are available with compression type process connections, suitable for gas flow ranges as low as 0-7.5 mLn/min, or in flanged or wafer style construction to fit from 38 mm (1.5') to 250 mm (10') line sizes, where flows of up to 11,000 m3n/h can be measured.

For many applications the requirement is for accurate gas mass flow control, rather than just measurement.

An option with Ex-Flow is to close-couple a control valve to the mass flow meter, to control the gas flow.

Several styles of valve are available, all with ATEX approved intrinsically safe or encapsulated coils suitable for use in a hazardous area.

For flow control, a simple intrinsically safe flow control loop can be achieved using the Bronkhorst E-7000 rack mounted digital readout system.

The E-7000 provides all the barriers and protection needed for the electrical control and measurement connections made into the hazardous area, for up to four EX-Flow channels per system.

In addition it displays mass flow rate, and as an option, provides RS232, Profibus-DP and Flow-Bus interfaces for external communication, allowing direct mass flow control from a supervising process control system or PC.

All Bronkhorst gas flow measurement systems are calibrated and configured for the actual gas and line pressure conditions relevant to the application.

With highly reliable no-moving parts thermal dispersion flow sensing, advanced microprocessor electronics and rugged packaging, GF Series Gas Flowmeters have are CSA certified in hazardous locations.

With their highly reliable no-moving parts thermal dispersion flow sensing element, advanced microprocessor electronics and rugged packaging, FCI high-performance GF Series Gas Flowmeter Models 03, 90 and 92 have received CSA certification for use in hazardous locations, including Class I, Groups B, C and D; Class II Groups E, F and G; Class III; and Type 4X: Class I, Division 2, Groups A, B, C and D. The GF Series features a flow rate accuracy of +1% of reading, plus 0.5% of full scale, with repeatability of +0.5 percent reading or better and extended calibration capabilities that allow for measuring in mixed, variable and changing gases. FCI advanced constant power thermal dispersion sensing technology provides the GF Series with turndowns up to 1000:1 with minimal pressure drop to achieve the wide ranges and lowest cost solution in industrial process gas applications.

There are no orifices or inlets to plug or foul, which greatly reduces maintenance.

It is ideal for use in rugged applications, where performance, durability, reliability and long-life are all important considerations.

The GF03 Flare Flowmeter is a single-sensing element, single-insertion point instrument that meets the accuracy, range and resolution required by the most stringent air pollution regulations at total installed costs of up to 50% less than alternative technologies.

Other flare flow sensing technologies, such as orifice plates and Venturi tubes, do not meet today's flare emission reporting regulations, are difficult to install, prone to excessive maintenance and have no simple technique for in-situ calibration validation.

Special time-of-flight ultrasonic products require up to four sensor insertion points (two flow sensors plus a pressure transmitter and a temperature sensor) most often in a cumbersome and costly spool-piece design.

Specifically designed for flare flow measurement and monitoring, the GF03 meets or exceeds regulatory agency specifications for +5% accuracy, repeatability of +0.5% of reading and a wide flow range from 0.50 to 275 SFPS.

Its performance and programmable outputs mean it is equally effective for reading and reporting both low flows, such as those occurring during a leak, as well as the high flow rates in a major flaring event.

Designed for tough plant environments, the GF03 sensor element operates in temperatures from -40 to 350F (-40 to 177C) and pressures to 100 psig (withstands up 1000 psig upset conditions).

Pipe connections include male NPT, ANSI flange, low and medium pressure packing glands and hot tap.

The GF90 offers unmatched performance and durability in a wide range of tough industrial flowmetering applications that include exhaust stack gas, digester gas and hydrogen composition gases.

Suitable for both low flow and high flow applications the GF90 ranges from 0.25 to 1600 SFPS [0.08 to 488 NMPS] at a standard temperature of 70degF and pressure of 14.7 psia [21.1C and pressure of 1.013 bar (a)].

It is available for use in pipe or duct line sizes from 2 inches (51 mm) and up.

The standard flow element has a 1-inch male NPT process connection and an application specific insertion length.

Flange connections and field retractable packing gland assemblies are also available.

The GF92 Flowmeter is specifically designed for gas flow metering applications in pipe sizes from 0.125 to 3 inches [3.2 to 76mm].

Flow sensitivity ranges from 0.006 to 2000 SCFM [0.01 to 3398 NCMH] at a standard temperature of 70F and pressure of 14.7 psia [21.1C and pressure of 1.013 bar (a)].

It has a standard body length of 7.25 inches (305 mm) for 1.5 to 3 inch pipe sizes-with custom lengths available upon request FCI is a global company committed to meeting the needs of its customers through innovative solutions to the most challenging requirements for sensing, measuring and controlling air, gas, liquid, flow, level and temperature.