Understanding the Operating Ranges and Statistical Profile of the Bartels Pump | BP7

This is Part 2 of our BP7 Performance Insights series.
If you haven’t read BP7 Performance Insights – Part 1: Stable Performance Needs Feedback yet, we recommend starting there. It explains how stable the BP7 micropump behaves under closed-loop operation and why consistent performance matters.

Start with: BP7 Performance Insights – Part 1: Stable Performance Needs Feedback

In this article, we open the lab door:
You’ll learn how we test the BP7 with both liquids and gases, under defined conditions, to gather data that helps quantify performance like flow rates, pressure levels, and statistical variation.

These results form the foundation of the specs we share in our product datasheets, providing system designers with a reliable basis to evaluate the BP7 for their specific setup, application, and performance requirements.

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Our Test-Procedure: How We Define the “Maximum” Performance Values

In our production line, each BP7 micropump is tested under standardized, highly controlled conditions to assess its peak performance potential:

For Liquids:

• Fluid: Water (degassed)
• Priming: Vacuum-primed to eliminate air and ensure full chamber filling
• System setup: Continuous recirculation with calibrated liquid flow and pressure sensor
• Drive signal: 250 Vpp at 100 Hz using an SRS (symmetric rectangle-sine) signal shape – generated by our mp-Labtronix
• Measurement: Flow and pressure is monitored under continuous drive and recorded in our database

For Gas:

• Gas: Dry air
• Priming: No priming required
• System setup: Continuous one-directional flow with calibrated air flow and pressure sensor
• Drive signal: Typically 250 Vpp at 300 Hz using using an SRS (symmetric rectangle-sine) signal shape – generated by our mp-Labtronix
• Measurement: Flow and pressure is monitored under continuous drive and recorded in our database

Real-World Flow Performance vs. Backpressure

The BP7 micropump can reach up to 14 ml/min and 500 mbar under lab conditions defined in our standardized test procedure (see section above). These values mark the upper end of the typical dynamic range.

In real-world applications, system backpressure, introduced by elements like tubing, filters, microfluidic chips, or valves etc., directly influences the achievable flowrate. The higher the backpressure in your setup, the further down you’ll operate along the curve, meaning the you will reach a lower flowrate at the same pump settings.

The graph shows this clearly:
As pressure increases, the flowrate steadily drops. The maximum flowrate (14 ml/min) is marked at low pressure and the maximum pressure (500 mbar) is marked where flow approaches zero.

The flow rate of the micropumps shows a linear dependency on the back pressure. At 0 mbar back pressure the maximum flow rate can be achieved and at the maximum back pressure the flow rate is decreased to 0 ml/min. The relation of pressure and flow rate is linear. 

Application examples A, B, and C demonstrate how different microfluidic system setups influence performance at the same parameters and pump settings:

• A: minimal resistance → near max flow
• B: moderate backpressure → mid-range flow
• C: high resistance → low flow

This highlights how test values provide a benchmark, but real-world integration defines actual performance and how closed-loop control can help compensate for such system-level factors.

Performance Specifications of the BP7 Micropump

These values are what you will find in our technical datasheets, and they represent the typical achievable flow and pressure values under optimal, controlled conditions.

The graph below is influenced by our test procedure. It visualizes how the BP7 micropump performs under defined conditions, based on extensive testing with liquids and gases across many production units.

These diagrams form the foundation for the key technical specifications we report, including:

• Typical dynamic range for flow and pressure
• Mean operating values
• Standard deviation
• 2-sigma performance range

Thanks to our 100 % end-of-line control, we collect and store complete performance data for every single pump. This allows us to present not just average values, but a full statistical distribution based on real-world units which offers predictable and reliable expectations for your system design.

Because the BP7 is manufactured in a highly automated, high-batch process, we’re able to offer a product that is both cost-efficient and scalable and therefore, ready for integration into large-volume applications.

This industrial-scale approach distinguishes us from hand-assembled or lab-only components. However, with high-volume manufacturing comes a defined yield: not every pump passes final testing, and only those that meet our quality criteria are shipped. The data you see reflects the performance of pumps that meet specification, giving you the confidence to design around it.

The BP7 micropump is designed for flexible operation across a wide range of flow and pressure requirements, both for liquids and gases. To better understand how the pump performs under different conditions, the following key specifications define its operating behavior:

Typical Dynamic Range

The typical dynamic range describes the full span of values the pump can reach during normal operation, depending on the medium:

• Liquids:
  • Flow rate: 0–14 ml/min
  • Pressure: 0–500 mbar
• Gases:
  • Flow rate: 0–35 ml/min
  • Pressure: 0–140 mbar

The upper end of the typical dynamic range reflects the mean value of our production yiel which corresponds to the peak of the Gaussian distribution observed in our standard deviation data. This value represents what most BP7 pumps consistently achieve under defined test conditions, making it a reliable reference point for system planning and integration.

Mean Operating Values

Under standard conditions (typically at 250 Vpp and 100 Hz for liquids or 300 Hz for gases) the pump achieves the following average performance:

• Liquids:
  • Flow rate: ~14 ml/min
  • Pressure: ~500 mbar
• Gases:
  • Flow rate: ~35 ml/min
  • Pressure: ~140 mbar

The mean operating values represent the peak of the standard distribution curve which is the point where most tested BP7 pumps perform under defined conditions.

These values also define the maximum of the typical dynamic range and provide a solid benchmark for most integration scenarios, offering a realistic expectation for system design and calibration.

In summary, the BP7 micropump combines a wide dynamic range with well-defined and statistically stable output, making it a strong fit for fluidic systems that require both flexibility and control. For more demanding setups, performance can be further enhanced using closed-loop control with flow or pressure feedback.

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What influences real-world performance?

Now that we’ve defined how we test the BP7 and where the performance numbers come from, the next step is understanding what those numbers mean in practice.

In BP7 Performance Insights – Part 3: Performance Challenges in Open-Loop, we take a closer look at how performance data like standard deviation and distribution affect interpretation and stability and how additional factors such as priming, air bubbles, low flow rates, pressure head, or media viscosity can influence system behavior.

Continue to BP7 Performance Insights – Part 3: Performance Challenges in Open-Loop