Have you ever experienced unstable readings, irregular dosing, or erratic vacuum levels when using micro diaphragm pumps? In precision systems like gas analyzers, IVD devices, or portable detectors, small flow fluctuations can cause big problems. I’ve seen OEM projects delayed or redesigned because pulsation issues were overlooked during the early design stages.
While flow rate and pressure specifications are often the first focus, pulsation—the rhythmic fluctuation in flow and pressure—plays an equally critical role. Understanding how pulsation originates inside a micro diaphragm pump and how it affects real-world performance can save you costly redesigns, improve system stability, and enhance sensor accuracy.
In this article, I’ll explain what pulsation really means, why it matters in precision applications, and how at BODENFLO we help engineers minimize pulsation to achieve stable, reliable, and high-performance pump systems.
How does pulsation happen inside a micro diaphragm pump?
In critical environments such as medical diagnostics, chemical sampling, environmental monitoring, or laboratory automation, pulsation can create significant risks. Here's why:
- Sensor Inaccuracies: Pressure-sensitive gas analyzers can misinterpret a pulsed flow as fluctuating gas concentrations, leading to false alarms or inaccurate readings.
- Component Stress: Constant micro-oscillations in pressure and flow can damage or prematurely wear down sensors, fittings, and membranes.
- Noise and Vibration: In portable and patient-facing devices, audible pulsation creates user discomfort and may introduce unwanted mechanical noise into sensitive measurements.
- System Instability: Pulsation can destabilize backpressure-sensitive systems, particularly when integrated with flow meters, filters, or precision dosing valves.
- Shortened Lifetime: Repeated mechanical stress on diaphragms, tubing, and check valves due to pulsation often reduces the operating life of the entire system.
Put simply: if your application needs stable flow or vacuum, pulsation is your invisible enemy unless you address it early in your pump selection and system design process.
What Causes Pulsation in Diaphragm Pumps?
Several intrinsic factors contribute to pulsation in diaphragm-based micro pumps:
- Reciprocating Mechanics: The diaphragm only moves fluid during the compression phase; during suction, there’s a temporary drop in flow.
- Inertial Lag: Even small-scale fluids exhibit inertia, causing a delay when reversing direction at the end of each diaphragm stroke.
- Valve Dynamics: Check valves have mechanical delay when opening and closing, which adds discontinuity to flow rates.
- Motor Control Type: Brushed DC motors and stepper motors can create additional flow irregularities during phase changes or switching.
- Medium Characteristics: Air, being compressible, tends to amplify flow variations more than liquids, which are incompressible and tend to dampen fluctuations.
Understanding these causes allows pump engineers and system integrators to predict, measure, and ultimately minimize pulsation effects.
How Is Pulsation Measured?
Pulsation measurement typically focuses on flow variation across a defined period.
The basic formula for pulsation amplitude is:
Pulsation (%) = (Peak Flow - Minimum Flow) / Average Flow × 100%
For example, if a pump’s instantaneous maximum flow is 4.2 L/min, its minimum is 3.6 L/min, and the average flow is 4.0 L/min, then:
(4.2 - 3.6) / 4.0 × 100% = 15%
In general:
- <15% Pulsation: Acceptable for high-precision sampling.
- 15–30% Pulsation: Acceptable for general-purpose pumps with external flow dampers.
- >30% Pulsation: Usually unacceptable for sensitive analytical or medical applications.
At BODENFLO, most of our premium series maintain pulsation levels below 10–12%, ensuring stable output across long operational lifetimes.
When Is Pulsation Acceptable—and When Is It Not?
It is crucial to know when pulsation must be minimized and when it can be tolerated:
✅ Acceptable Pulsation:
- Air mattress inflation
- Pneumatic actuation for simple mechanical tasks
- Cooling airflow generation
✅ Unacceptable Pulsation:
- Gas chromatography sample injection
- In vitro diagnostic (IVD) reagent dosing
- Portable gas analyzer sample feeding
- Vacuum stabilization for membrane separation
General rule:
The more critical the process precision and measurement sensitivity, the lower the pulsation tolerance must be.
How Can Pulsation Be Reduced?
Many practical strategies exist to minimize pulsation, even within small form factor designs:
- Multi-Head Configurations: Pumps with two or more diaphragms phased apart can significantly overlap flow cycles, smoothing output.
- Pulsation Dampers: Small buffer volumes or accumulators positioned downstream can absorb flow fluctuations.
- Motor Tuning: Brushless DC motors allow much smoother operation by offering better acceleration/deceleration control.
- Check Valve Optimization: Using lightweight, fast-reacting valves can minimize flow interruption between strokes.
- High-Frequency Drive: Operating pumps at higher frequencies with smaller stroke volumes naturally smooths flow.
- Flexible Tubing Integration: In some designs, elastic tubing sections act as dynamic accumulators to absorb pulse shocks.
For applications requiring ultra-low pulsation (<5%), combinations of multiple methods are often deployed.
BODENFLO’s Low-Pulsation Micro Pump Solutions
At BODENFLO, low pulsation isn't optional—it’s engineered into our DNA.
Our flagship products like the BD-05T brushless diaphragm pumps series feature:
- Dual-head parallel architecture for smoothing flow cycles
- Brushless DC motor drive systems for jitter-free motion
- Compact dampening chambers integrated internally
- Diaphragm and valve materials optimized for fast response and chemical resistance
Typical applications where our low-pulsation pumps dominate include:
- Portable VOC analyzers
- Blood gas analyzers (BGA)
- Smart agriculture environmental sensors
- Mobile emissions monitoring
By partnering early with our clients during development, we help ensure fluid control performance that meets even the most demanding specifications.
Real Case Study: Pulsation Elimination for a European Gas Analyzer
In early 2025, a European environmental OEM contacted us.
They faced stability issues in their portable CO₂/NO₂ gas analyzers: pressure spikes were throwing off sensor calibration.
After analyzing their system, we replaced their existing pump with a customized BODENFLO BD-05T dual-head setup, tuned the motor speed for continuous duty operation, and added a miniature damper right after the pump.
The result:
✅ 92% pulsation reduction
✅ ±2% flow stability over full temperature range (-10°C to +50°C)
✅ 10,000+ hours field operation durability
Their product is now ranked among the top three in the European air quality portable device sector.
Conclusion
Pulsation is one of the hidden factors that silently defines whether a microfluidic system succeeds or fails.
Choosing a micro diaphragm pump with optimized pulsation control—such as those from BODENFLO—ensures:
- Higher device precision
- Longer operational lifespan
- Lower service costs
- Better customer satisfaction
Don't overlook pulsation when selecting your next-generation micro pump. Build it right from the beginning.
📩 Need help optimizing your system? Contact us at info@bodenpump.com
