Advanced functionalities™
of FLEXI-FLOW instruments
Bronkhorst Mass Flow & Pressure Meters and Controllers of the FLEXI-FLOW series offer exceptional ease of use as well as additional capabilities
that can reduce space and costs for additional parts, instrumentation or software. In this datasheet we provide a collection of these features,
describing their advantages and benefits for users of our FLEXI-FLOW instruments.
Flow/Pressure control
In general, monitoring upstream and/or downstream pressure while controlling the gas flow could warn the user via a NAMUR message for unexpectedpressure drops or increases caused by leakage or clogging.
In some applications, the combined use of flow and pressure measurement
can be advantageous, for instance at hydrogenation in catalytic processes.
FCThe supply of hydrogen must be accurately monitored, while increasing thepressure in the reactor. A FLEXI-FLOW instrument can be applied as forward
pressure controller with flow restriction, maintaining the maximum feed ofForward pressure control with flow restriction
H2 within the limits of the flow sensor. A traditional pressure control set-up
with separate flow meter would not restrict the H2 overshoot (> Full Scale)and thus provide an incorrect measurement of the total amount of H2 that has entered the reactor.
This principle of combined flow/pressure control can also be applied for e.g., performing leak tests
or for testing the porosity of filters.

ProcessPI

Alternatively, the flow/pressure control combination can prove to be beneficiary in systems where the flow
should be restricted because the upstream or downstream pressure reaches its minimum respectively itsmaximum limit. This may, for instance, be applied to protect fragile reactors for overpressure or to prevent
particle generation.
Operational history / data logging
Logging process data could be helpful for engineers to comply with security policies or regulations, or fortroubleshooting, trying to find an explanation for certain deviations. A separate data logging device may
become superfluous when using FLEXI-FLOW, because the instruments can provide a comprehensive history(minimum, maximum, standard deviation and average values) of the past 24 hours, 30 days and lifetime for:measured flow
measured upstream and downstream pressure
setpoint (flow/pressure)temperature
actuator output
User stories	"We directly improved product quality by using Bronkhorst instrument parameters. By measuring the device
internal temperature and detecting temperature variations we were able to improve our processes."	"In our process, we make use of the response alarm to monitor if an MFC reaches and maintains its setpoint within specified limits. This is helpful to know if
an inlet pressure is too low, when a gas bottle is almost depleted, or to detect obstructions in the system."	"The power-up alarm message, in combination with the function to return to the last setpoint after a power failure proved to be useful. We were happy
that our bioreactor process directly continued after a detected power dip."	"By following the relation between the values of measure and valve out over time, we can detect if something has changed in the setup. This can be theinlet pressure, but can also be clogging or wear of components somewhere in the setup. Maintenance can be considered if we observe such a change.""In our R&D environment, we use a variety of bottled gases. The inlet pressure measured by our FLEXI-FLOW instruments warns us when a gas bottle isalmost empty, thus preventing an unexpected interruption of our experiment. An orange NAMUR message signals “insufficient pressure difference”.
This message could also be triggered by an (unintended) increase of the back pressure caused by an event in the downstream process."

DATASHEETNAMUR NE107 diagnostics
At FLEXI-FLOW, the instrument’s status is visualized by means of coloured LEDs on top of theelectronics housing. This allows the user to see immediately that an instrument is displaying a warning.
FLEXI-FLOW instruments provide the user with a wide range of digital parameters. These can beused for extended measurement or control functionalities, but also for continuous monitoring of theinstruments and its process conditions. This valuable information can be used by maintenance systems
to optimize the process and minimize the system’s downtime.
The parameters mentioned in this document are a selection from an extensive parameter list, which
can be found in the FLEXI-FLOW instructional manual (9.17.158). This parameter list is extended
regularly with new insights and requests from customers. All instrument parameters are continuously
available with any digital interface. Our implementation of digital interfaces is built up according tostandard profiles for ultimate compatibility and convenience.

Green

Normal operation

Red

FailureYellow

Out of specifications

Blue

Maintanance required

OrangeCheck function

Python / LabVIEW™
Bronkhorst provides drivers for LabVIEW™ and Python that implement the serial RTU commands used on
the FLOW-BUS, Bronkhorst’s protocol which is generally used on all our digital instruments. FLEXI-FLOWinstruments, however, feature advanced functionalities. Thanks to the modular set-up, customers caneasily modify our drivers according to their requirements.
BluetoothIn research institutes or at laboratories of universities and factories, fume cupboards with safety glass areapplied to protect their staff from emissions from small scale processes or other experimental set-ups.
Here, the degree of automation and the operation of the electrical components is often limited to theessentials. This is where the Bluetooth wireless transmission option of FLEXI-FLOW instruments comes inhandy. The cupboards can remain closed when querying the process values and the test run or process
does not need to be interrupted. Beyond safety, it is also a cost-effective solution since free apps areavailable for smartphones and tablets with intuitive operating software.
In industrial plants, system operators prefer to use one automation platform for all process components.
The use of additional operating software is usually not allowed, for safety reasons. Apart from the ability to monitor an instrument during production cycles,
FLEXI-FLOW's Bluetooth option offers the benefits of easy data retrieval, analysis, function check or commissioning, even in cramped installation conditions.
USB-C / Parameter monitoring
FLEXI-FLOW's USB-C connection offers the possibility of support/monitoring without having to take the instrument out of operation. Measurement, control
and diagnostic parameters are of interest to monitor process conditions and set instrument messages that indicate a potential issue in the overall system. The
parameters can also be used as possible indicators for maintenance.
In the tables below we listed the most used parameters with some typical suggestions for their application.
Diagnostics

Indicative parameters

Notes for use

Preventive maintenance

operation hours

input for maintenance schedulecalibration date

input for recalibration schedule

operational history

onboard data logging for capturing historical data

power-up alarm message

informs the user that device has been rebooted due to loss of power

hardware alarm message

detection of hardware issues; message for trouble-shooting

NAMUR status indicationeasy recognition of the status (self-monitoring)

communication failure message

diagnostic info of (fieldbus) communication interface

inlet pressurelow value may indicate that inlet pressure is insufficient for the process

outlet pressurehigh value may indicate possible blockage in downstream process line

temperaturemonitored value may indicate potential problems

flow

measured signal may indicate overflow or underflow

valve output

high value may indicate possible blockage in downstream process line

response alarm

setpoint is not reached within the time limit

min/max alarm

flow exceeds a minimum or maximum level

Electrical failure detection

Process failure detection

DATASHEET
Bronkhorst High-Tech B.V.
Nijverheidsstraat 1aNL-7261 AK Ruurlo, The Netherlands

Tel. +31 573 458800
info@bronkhorst.com
www.bronkhorst.com©Bronkhorst® 230406A