Page 16 - Industrial Technology EXTRA 25th January 2021

dosing points. It is an important process that is and warning thresholds can also be developed by
ideally suited to genomics, and processes in the Bürkert on request. In addition to accuracy and
pharmaceutical sector. consistency, Bürkert has also paid close attention to
the materials that are used throughout its products.
Maintaining accuracy As an experienced supplier to many industry sectors
Time pressure dosing uses a pressurised carrier gas that handle aggressive liquids, as well as needing to
to optimise the performance of the dosing valves meet stringent hygiene standards, Bürkert uses a
that dispense micro-volumes of reagents as part of range of materials to match the chemical resistance
an automated process. This method of liquid requirements of the application.
measurement provides continuous dosing, saving The latest development by Bürkert can be
time compared to refilling a syringe pump. It is also combined with a range of dosing valves, all
free from downtime or rejects at the beginning of designed with media separated actuators
dosing cycles, reducing overall production time and constructed using the most appropriate materials.
wastage. This also extends to the Type 8763, where the
However, each time the dosing valves operate, pressure inlet is only exposed to air or inert gases.
the pressure in the reagent storage vessel drops However, the vent port may be in direct contact
slightly and, unless this is corrected, the dosing with solvents and so can be specified from a list of
volumes will gradually decrease. It is therefore materials including PPS and FFKM.
essential that the supply pressure in the tank is
constant and stable. Flexible communications
Bürkert’s Type 8763 closed-loop controller Instruments used in laboratory applications need to
ensures that stable dosing of microlitre volumes is record data and be capable of sharing information
provided, even with minimal pressure difference with a wider network. The digital interface of the
between dosing cycles. Functionality such as an Type 8763 also enables parameters to be changed
additional pump or pressure sensor can also be while the system is running for improved control
added through a further sensor input and actuator flexibility. Automated process documentation
output. increases process safety and access to data is also
High-accuracy repeatable dosing is supported possible during system operation.
with active pressure relief for precise regulation, The digital variant of the Type 8763 pressure
while bidirectional control can increase or decrease controller communicates over Bürkert Systembus
pressure in the storage vessel. This delivers short (büS), based on the CANopen protocol with
response times, which ensure immediate and additional functions. The pressure controller joins
reliable pressure control. Bürkert’s Efficient Device Integration Platform
The Type 8763 is available in three pressure (EDIP), which enables intelligent networking down
ranges and both analogue and digital variants, with to sensor and actuator level over büS connectivity.
the latter also incorporating analogue control. Industrial communication standards including
Digital communication achieves optimum process PROFINET, PROFIbus, Ethernet and Modbus/TCP
parameters by running defined pressure cycles to are supported to enable flexible integration of
specific programs, which can be set according to system components.
application requirements. Predeveloped, bespoke The pressure controller is simple and quick to
programs with features including pressure curves set up with plug-and-play functionality and no

January 2021 • INDUSTRIAL TECHNOLOGY EXTRA • p16