Products » Laminar Differential Pressure (DP) Flow Devices
Laminar Differential Pressure (DP) Flow Devices
Multi-variate sensing of pressure, temperature, and flow in one device
Alicat® Scientific’s laminar differential pressure (DP) technology is the core measurement principle behind our mainline mass flow meters and mass flow controllers, trusted for speed, stability, and precision measurement. Converting turbulent flow into smooth laminar flow and applying the Poiseuille principle, our instruments deliver fast, stable, and highly accurate flow data for gases and liquids. Their highspeed measurements and control are favored for R&D, manufacturing, advanced energy systems—and more.
Benefits of laminar DP flow technology
- Multi-Variate: Mass flow, volumetric flow, pressure, and temperature, all in one device
- Versatile gas compatibility: Select from up to 130 gas calibrations, or blend up to 5
- Ultra-fast response: < 5 ms measurement; ~30 ms control response; 1 s warm-up time
- Wide dynamic range: 0.01% to 100% of full scale, up to 10,000:1
- Optimized control: Factory-tuned PID with in-situ autotune for fast, stable control
- Pressure control loop: switch to measure mass flow rates while controlling on pressure settings
- Proven reliability: Trusted globally in research, manufacturing, aerospace environments and more
Choosing the right flow technology. Each flow measurement technology offers unique strengths. Compare Laminar DP, Coriolis (CODA), and Thermal MEMS (Basis) to find the right fit for your application.
How laminar flow differential pressure enables mass flow measurement
What is laminar flow?
In fluid dynamics, flow can be turbulent (chaotic and unpredictable) or laminar (smooth and orderly). Laminar flow is easier to model and measure because velocity is distributed in predictable layers.
Read more: Laminar vs. turbulent
Understanding laminar flow is key to Alicat’s precision. Our laminar flow elements (LFEs) convert turbulent gas or liquid into laminar flow, creating a linear relationship between pressure drop and flow rate. Combined with temperature and absolute pressure sensors, this enables mass flow calculations for known viscosities, not just volumetric readings.
How laminar DP instruments work
Alicat laminar DP devices measure mass flow by combining differential pressure, absolute pressure, and temperature readings with the Poiseuille equation.
- Step 1: Flow Conversion. The laminar flow elements (LFEs) channel turbulent flow into smooth laminar flow through an array of parallel passages.
- Step 2: Pressure & sensor measurement. Differential pressure, absolute pressure, and temperature sensors capture real-time flow conditions.
- Step 3: Volumetric flow calculation. The Poiseuille equation relates the measured pressure drop to volumetric flow rate.
- Step 4: Mass flow calculation. The instrument applies density corrections for the temperature, pressure, and gas compressibility, to determine standardized mass flow.
This multi-sensor approach enables stable, repeatable readings across wide dynamic ranges and varying conditions.
Alicat’s family of laminar DP mass flow meters and mass flow controllers
Available Variants
MQ Series Meter
Measure flow rates at higher pressures
MS Series Meter
For a wider range of gases
BIO Series Meter
Gases into and out of bioreactors and fermenters
Available Variants
MCQ Series Controller
Control flow at higher pressures
MCS Series Controller
Corrosion resistant flow control
MCD Series Controller
Control flow in two directions
MCT Series Controller
Switch between two gas streams
SFF/MCV Series Controller
Control at vacuum pressures, SEMI footprint options
Customer stories
By working closely with researchers and engineers, we help solve challenges in real-world systems. These stories highlight how Alicat Scientific’s mainline laminar DP flow instruments support critical processes across a range of industries.
Indoor and Vertical Hydroponic Systems
Hydroponics has become one of the most significant innovations in modern agriculture. By eliminating soil and tightly controlling environmental conditions, growers can achieve faster growth rates, higher yields, and more efficient use of resources. The...
Slabstock Polyurethane Foam Production with Alicat
Urethane molecule Polyurethane (PU) foam is a versatile, spongy plastic foam which is common in household and consumer products. It’s inside of mattresses and cushions, kitchen sponges, thermal insulation, yoga mats, toys, and shoe soles. Chances are if...
Mass Flow and Pressure Control for Gas Chromatography
By Mike ZecchinoAccurate gas chromatography (GC) analysis depends upon the consistent flow/pressure of the sample and carrier gases through the apparatus. Alicat instruments have numerous applications to ensure accurate measurement and control of flow and...
Portable Flow Meters for Industrial Hygiene Calibration
Industrial hygiene is the science of protecting and enhancing the health and safety of people at work and in their communities. Federal organizations including OSHA and the NIOSH strictly enforce industrial hygiene regulations to ensure workers are safe from...
Supported applications
By working closely with our customers, Alicat has fostered a collaborative environment to help build custom solutions for critical processes, here are a few of the industries.
Fuel cell testing & hydrogen research
Benefits of laminar differential pressure (DP) devices for fuel cell testing
- Fast response (<50 ms) and wide 10,000:1 turndown for stable fuel cell control.
- DP controllers handle up to 12,000 SLPM with accurate, moisture-tolerant sensing.
- Dual-valve controllers maintain precise pressure for safe, repeatable testing.
- Low-pressure drop meters (0.07 PSID) enable sensitive leak and membrane checks.
Bioreactors & bioprocessing
Benefits of laminar differential pressure (DP) devices for bioprocessing systems
- Wide 10,000:1 turndown enables one device to cover high- and low-flow gas lines.
- Accurate low-flow control reduces the number of lines from 5 to 3, cutting bioprocess costs.
- Fast response (<1 ms sensor) keeps oxygen and air delivery stable during growth.
- Moisture-tolerant DP meters maintain accuracy with humid or wet gas streams.
Gas chromatography (GC)
Benefits of Laminar Differential Pressure (DP) devices for GC
- Stable carrier and sample gas control improve GC repeatability and accuracy.
- Totalizer logging supports calibration certainty and process diagnostics.
- Fast meters (<10 ms) detect vented gas changes for reliable downstream checks.
- Absolute or gauge pressure control simplifies GC setup and reduces variability.
Valve leak testing in space exploration
Benefits of laminar differential pressure (DP) devices for leak testing
- Dual-valve controllers regulate pressures up to 3,000 PSI with high repeatability.
- Low-pressure-drop meters detect small leaks at near-atmospheric conditions.
- Multi-gas calibration enables fast switching between helium and nitrogen.
- AS5202-compatible devices integrate easily into aerospace test systems.
Support & Resources
Manuals
Flow measurement guides & technical resources
Ask an engineer
Our Applications Engineers can answer your questions and help you find the best option.
Call us
+1 (888) 290-6060
Live chat
Ask us a question
Help near you
Find a local representative
Tech docs
Reference materials