2Efficient and reliable UHPLC pump maintenance - Self-diagnostics using Digital Twin
Table of contents
Table of contents
1. Overview
2. UHPLC pump symptoms
3. Current approach
4. Diagnostics 2.0
• Digital Twin & autonomous diagnostics
• Recommendations & fixing instructions
• User benefits
5. Future-proof
3Efficient and reliable UHPLC pump maintenance - Self-diagnostics using Digital Twin
1. Overview 2. UHPLC pump symptoms
1. Overview
2. UHPLC pump symptoms
Ultra High Performance Liquid Chromatography (UHPLC) pumps are
used in laboratories all over the world. These instruments can pump
mobile phase solvents with a very accurate flow rate over a large
pressure range.
To meet nowadays laboratory requirements and assure this excellent
precision performance the flow rate of the pump has to be constant
over the pressure range (0 - 1300 bar). The smallest deviation in
pressure and/or flow can be an indication of an (upcoming) defect
in which the reliability of the analysis of the samples is at stake.
To ensure good, stable pump performance and maximize instrument
uptime, it is necessary to closely monitor the pump’s operation. That is
why Spark Holland is implementing a state-of-the-art diagnostic tool
for its UHPLC pumps that makes it possible to carry out accurate
diagnoses and detect if a component of a system is (not) operating
properly. The diagnostic tool is created using Digital Twin technology,
developed in collaboration with industry experts, and allows for
monitoring of the most important Key Performance Indicators.
The patent pending diagnostic tool will bring substantial analytical and
problem-solving advantages and represents next level customization.
This autonomous intelligence will enable service engineers to find,
locate and fix problems quicker, more easily and accurately, and
improve instrument uptime significantly.
An UHPLC system consists of many components and performance
issues can arise, often caused by known wear parts, like check valves
and sealings, or aging of the system during lifetime. Most of the
common symptoms of UHPLC pumps concern:
• shifting retention times
• baseline drift
• pressure fluctuation
• lower column back pressure
The challenge for a service engineer is to efficiently identify the most
likely cause of each symptom, but how?
4Efficient and reliable UHPLC pump maintenance - Self-diagnostics using Digital Twin
3. Current approach
3. Current approach
Many service engineers opt for corrective and/or preventive
maintenance, with or without certain diagnostics, for UHPLC pumps.
Corrective or reactive maintenance is failure-oriented and aimed at
quick recovery when a UHPLC pump is not working properly and the
operation of a UHPLC system is compromised. Troubleshooting guides
can help to identify, isolate and correct an issue. However this process
can be time consuming and disappointing, when it involves trial and
error. Lack of technical knowledge, may even result in the unnecessary
replacement of parts that are not defective. Thus, for instance, an entire
pump head may be replaced when only the seal, as a wearing part,
would need to be replaced. As a result, maintenance becomes more
expensive.
Preventive maintenance is planned and scheduled. It can be
performed by inspecting a pump more regularly to prevent downtime.
It involves inspections according to a maintenance program, at fixed
intervals to replace parts before they can cause problems because of
wear. The interval depends on system usage but is usually set to once
per year out of convenience which might not be sufficient for all users.
In addition, this periodic check requires more frequent testing in a
specific test setup with operational interruption and, like corrective
maintenance, accurate record keeping.
Preventive maintenance kits concern:
• high pressure seals
• low pressure seals
• check valves
• solvent filters
• inlet filter
• pistons
• purge valve rotor seal.
Corrective and preventive maintenance can cause unnecessary
downtime due to, for example, lagging technical expertise or
insufficient maintenance capacity. Also, both types of maintenance
require confirmation that the pump performance is according
expectation after maintenance. That validation can be obtained
with Diagnostics 2.0.
5Efficient and reliable UHPLC pump maintenance - Self-diagnostics using Digital Twin
4. Diagnostics 2.0
4. Diagnostics 2.0
UHPLC systems are complex and it is a great challenge for a service
engineer to master all parts of the system, both in terms of operation
and troubleshooting. The UHPLC pump alone requires a great deal of
technical knowledge, which is not always present. This also applies to
the troubleshooting tools that are commonly used. The level of
knowledge and skills of the service engineer is leading for successful
diagnostics and troubleshooting.
Service engineers and maintenance departments are always looking
for better ways to guarantee or restore the performance of UHPLC
systems. This means easier, quicker and more reliable ways to keep the
systems and its modules operational and minimize unnecessary
downtime. In short, they want the best reliability strategy for maximizing
uptime of their UHPLC pumps.
Based on her years of experience with Digital Twin, Spark Holland
concludes that her diagnostic tool for autonomous testing is a valuable
and very reliable addition to existing methods of maintenance and
diagnostics.
A Digital Twin is a highly accurate, virtual working model of an
intended system (product or service) in a given environment.
Within the innovative manufacturing industry, a Digital Twin is
widely used today. A Digital Twin is constructed based on the
same natural laws and principles as a system in the real
world. The way a Digital Twin behaves in its virtual world is
almost identical to its physical counterpart.
Designing with a Digital Twin has great advantages. The
system design can be optimized by engineers at an early
stage, with or without customer feedback, before it is put into
production. Furthermore, it enables several design concepts
to be virtually validated in advance. This saves time and
money, also because fewer physical prototypes are needed.
In short, the engineering process is more efficient while at the
same time it is more thorough. This also applies to further
development and modification of the product/system. An-
other advantage is that the development of hardware and
firmware can run in parallel with the mechanical design,
which again saves time.
A Digital Twin of a product consists of data (the digital base)
and models related to requirements, form, structure, calcula-
tions, specifications and simulations of a product. At Spark
Holland, the mechanical domain of a Digital Twin is devel-
oped at the start of the mechanical design to validate its
ability to meet product requirements. With the system
description that the Digital Twin offers at that stage, engineers
are able to simultaneously start with the design of electronics
and firmware. When the design has reached the required
level of detail, prototypes can be produced and tested. By
collecting data from physical prototypes, for example on flow
and pressure, the last details of the Digital Twin are tuned in
order to represent the physical system as accurately as
possible. With this approach the Digital Twin forms an addi-
tional design layer, which helps engineers analyze a system
more thoroughly and foresee problems before they occur.
In addition to the benefits of developing a Digital Twin during
the design process, the Digital Twin also allows to perform a
multitude of experiments in a short time. Furthermore, a
Digital Twin is capable to consistently and repeatedly simu-
late the system behavior with worn wear parts in a controlled
environment, which is difficult to achieve on a physical system.
These properties allow engineers to develop state-of-the-art
diagnostic tools based on machine learning. These tools help
field service engineers to faster locate worn components
causing an underperforming system, saving time and costs.
6Efficient and reliable UHPLC pump maintenance - Self-diagnostics using Digital Twin
4. Diagnostics 2.0
Digital Twin & autonomous diagnostics
In its continuous ambition for optimizing UHPLC modules, Spark Holland
uses a Digital Twin model. This model facilitates the development of
UHPLC pumps in two ways:
- Design: to optimize the system design in terms of firmware,
mechanics, etc.,
- Diagnostics: optimizing the diagnostic performance.
Spark Holland has developed its diagnostic tool to make pump system
information more accessible to service engineers. Because the
diagnostic tool was developed with Digital Twin technology, Spark
Holland can introduce an efficient and reliable way of diagnostics. The
separate tool enables automatic monitoring of pump operation within
a control system.
Using this autonomous diagnostics tool, a service engineer or user can
diagnose whether a pump is operating within the parameters of that
equipment, or the manufacturer’s prescribed performance objectives.
The diagnostic tool validates whether the observed values of the
physical system match the calculated results of the model.
During the diagnostic process, analysis takes place with the help of
machine learning. This package contains data for almost 100 different
Key Performance Indicators (KPIs) and recognizes abnormalities or
patterns of error. Spark Holland has made the data very accessible.
The output is presented from a PC in an understandable form to the
user. The service engineer doesn’t need to analyze a log file, but can
suffice with on-site review of the analysis made by the diagnostic tool
of the detailed data.
Recommendations and fixing instructions
The diagnostics tool not only helps analyze information very quickly,
but also locates any inaccuracies or discrepancies, for example the
anomalous behavior of a check valve, and advises the user how to fix
it (recommendations and instructions).
7Efficient and reliable UHPLC pump maintenance - Self-diagnostics using Digital Twin
4. Diagnostics 2.0
User benefits
Spark Holland’s diagnostic tool takes troubleshooting off the hands
of engineers as it takes over the interpretation of the pump’s actual
operation. Troubleshooting takes many recurring, standard steps out
of the hands of the service engineer, allowing him to focus more
(efficiency) on fixing rather than analyzing an anomaly or problem.
The main user benefits of the Spark Holland diagnostic tool are:
• Locating problems and solutions,
• Better understandable and comprehensible data (easy
readable interface),
• Faster and easier troubleshooting and fixing,
• Reduce unnecessary part exchange,
• Higher uptime.
Maintenance procedure using Diagnostics 2.0
Using the diagnostic tool the UHPLC pump maintenance procedure becomes
as follows:
1. Diagnostic routine: select test and click ‘start’ to open the wizard that
interactively guides you through two steps:
a. Initialization: pump initialization and check parameters (sensors, drives,
cables etc.) in order to determine if the diagnosis can be performed.
b. Analysis: automatic priming and purging, increase flow rate, pump
during several minutes, determine secondary seal leakage, extract
logfile and run diagnostics & detect patterns.
2. Results: check the automatically presented feedback with visual indication
of the location of the failing part.
3. Recommendations: click ‘next’ to get instructions for solving the problem.
4. Follow-up: implement the recommendations by, for example, calibrating the
pump and replacing parts.
5. Validate: validate the solution by running steps 1 to 4 again until the problem
is solved.
The tests are performed with water and total test times takes 15-20 minutes.
8Efficient and reliable UHPLC pump maintenance - Self-diagnostics using Digital Twin
5. Future-proof
5. Future-proof
By applying Digital Twin technology for its UHPLC pumping systems,
Spark Holland supports service engineers in their efforts to make the
maintenance processes more effective and reliable (> 90% accuracy
thanks to the smart use of lots of available data) and increase system
uptime.
The diagnostic tool can be used as an additional tool for maintenance
and troubleshooting a problem, but also provides capabilities for future
real time diagnoses and forecasts (predictive maintenance), as well as
for integration into software programs of OEM partners. In other words,
the diagnostic tool is future-proof for anyone who wants the best
reliability strategy for UHPLC pumps. •
Patent pending
Spark Holland has a patent pending for the diagnosis of a controlled LC
pump unit:
- Patent pending diagnostics EP 3 992 626 A1
- US20220128522A1 US20220128522A1 Training a neural network processor
for diagnosis of a controlled liquid chromatography pump unit - Patent View
- PatSnap
Training a neural network processor is described for providing diagnostic infor-
mation of a controlled liquid chromatography pump unit. The training includes
executing a sequence of operations wherein the neural network processor is
trained with input signals obtained from a simulated version of the controlled
liquid chromatography pump unit and associated sensors, while modifying the
simulated version of the liquid chromatography pump unit to a pump fault
simulation signal. Dependent on a value of the pump fault simulation signal, the
simulated version of the liquid chromatography pump unit simulates operation
of the liquid chromatography pump unit free from faults or the operation thereof
with one or more pump faults. The trained neural network processor obtained
therewith is thereafter integrated with a controlled liquid chromatography pump
unit to provide for auto-diagnostic capabilities or used in a separate diagnostic
unit for diagnosing one or more controlled liquid chromatography pump units
not having auto-diagnostic capabilities.
