Portable Air Flow Test StandProduct Summary

The Portable Air Flow Test Stand (PATS) is a compact air flow measurement system specially designed for highly accurate and repeatable measurement. It measures air flow for aircraft and land-based, gas turbine parts, and meets a wide range of component flow range air testing needs of OEMs and their suppliers.

Key Features
  • Portability (fits in a transport case or on a work bench)
  • Highly Repeatable Results (±0.25%)
  • Accurate Measurement (±0.48%)
  • Uses up to four automatically selected sonic nozzles
  • Highly customizable controller software for test automation and data management
Related Products for Measuring Different Flow Ranges

The PATS is one in a series of air flow test stands designed for the aerospace and turbine engine-based component industries. These test stands are designed to provide complete, automated solutions for flow measurement.

For information on related products, read the Air Flow Test Stand Product Comparison.

Complies with OEM Test Specifications

OEMs and their suppliers worldwide require quality airflow measurement of passages in both aircraft and land-based turbine engine components. Each OEM has a unique testing specification and their suppliers must be flexible with the test procedures in order to comply with each OEM test specification. Accuracy, repeatability, throughput and availability are critical elements in the design of these test systems. These air flow test systems currently comply with the in-house testing procedures of ABB/Alstom Power, ABB Gas Turbines, Pratt & Whitney America, Pratt & Whitney Canada, General Electric Aircraft Engines (General Electric Infra, Aviation), General Electric Power Systems (General Electric Infra, Energy), Honeywell, Mitsubishi Power Systems, Mitsubishi Heavy Industries, Allison Engine, Rolls-Royce, Solar Turbines, Siemens, Siemens-Westinghouse, Snecma, and many others.

Traceable to NIST

All Flow Systems air test stand sonic nozzles and instruments are traceable to National Institute of Standards and Technology (NIST).

System Specifications
Specification Value(s)
Flow Elements 0.016″ – 0.250″
Air Mass Flow Range Performance Configuration 1:CFV’s:  0.063, 0.125, 0.177 and 0.250”0.002 to 0.2 lbm/sec

If PR=1.25 à Ae: 0.005 to 0.59 in2

Configuration 2:

CFV’s:  0.031, 0.063, 0.125 and 0.250”

0.0006 to 0.15 lbm/sec

Configuration 3:

CFV’s:  0.016, 0.031, 0.063 and 0.125”

0.00015 to 0.05 lbm/sec

Part Pressure Range 1 – 10 psig, custom range available
Part Pressure Ratio Range 1.07 – 1.68, custom range available
Uncertainty ±0.48% of reading, NIST traceable
Repeatability Estimated better than +/-0.15% as defined as 2 standard deviations divided by the mean of 20 identical samples.  Included in uncertainty above and may encompass effects from air supply, flow bench, plenum and connecting volume and part.
Cycle Time 20 – 60, capacity depenedent
Connections Flow Ports Air In: 3/4″ (-12) Swagelok QF Female
Air Out: 1″ (-16) Swageelok QF Female
Pressure 1/4″ (-4) CPC Female Quick Connectors – PLC series, color-keyed
Case Dimensions 21″ L x 19″ W x 14″H
Case Dimensions 32″ L x 24″ W x 17″ H
Unit Weight 55lbs (105lbs with case and three hoses)

Uncertainty Analysis

Per the ISO Guide to Uncertainty in Measurement (GUM).  Contact Flow Systems for more detailed information.


National Instruments LabVIEW Logo
Control System Operator Interface

The system controller software handles the opening and closing of sonic nozzle flow paths, sets the proper pressure at the inlet of the Unit Under Test and calculates the mass flow through the sonic nozzle manifold. The controller also monitors the airflow conditions to ensure the sonic nozzles are in a “choked” state and that the flow is stable. Controller software is written using National Instruments LabVIEW™.

Report Live Data and Compare to Historical Data
  • On-screen tabular and graphical results are displayed in real-time
  • Variety of user-customizable reports
  • Allows the operator to read all system sensors, read status and error messages
Customize Controller Software and Integrate Data
  • Controller software can be customized to fit a wide variety of customer needs
  • Data can be integrated with customer’s local databases and/or information systems
Data Storage Formats
  • Standard storage format is SQL database
  • Customized data storage options available
Determines Test Measure Value Ranges of a Part
  • Allows the operator determine the “test measure” or flow value without knowing anything about the part other than the test setpoint
  • Used primarily for research and development to determine the test measures of a new or test part
  • Sets an upper and lower acceptance limit based upon the measured value and a user defined tolerance
Monitor Performance using Statistical Process Control (SPC) – Optional
  • SPC features provide the customer a method for monitoring the performance of the Unit Under Test in real-time and in relation to previous production parts to identify variations in the part production process
  • Develop and manage flow test configurations in conjunction with shop floor controlling information system
  • SPC features can be customized to suit customer’s quality control criteria
Determine Average Value & Repeatability of Master/System Unit Under Test
  • Measures the repeatability, average and percent difference (measured to calculated) of a series of consecutive flow tests through a master part test
  • Allows the flow results of a master part to be included in the test report for other production parts, which allows the repeatability of the test bench to be monitored over time
  • Performs test stand audits by measuring the repeatability, average and percent difference of a calibrated master sonic nozzle against the installed system nozzles
Tests and Suggests Proportional-Integral-Derivative (PID) Parameters
  • The system flows the Unit Under Test and uses the natural response of the system to calculate Proportional-Integral-Derivative (PID) parameters
Troubleshoot & Diagnose System and Part Leaks
  • Leak Test Diagnostics: Test the system and attached customer part fixtures for leaks
  • Critical Flow Venturi (CFV) Valve Leak Check Diagnostics: Determine the seal integrity of the CFV valves
  • Manifold Leak Test Diagnostics: Determine the leakage of internal test stand pressure manifolds to ensure integrity of test stand
  • Data Acquisition Device Diagnostics: Self-check to determine status and communication with data acquisition hardware and instrumentation
Troubleshoot Issues Using Internet-based Support – Optional
  • After connecting the test stand to the internet, receive technical support from Flow Systems
Additional Software Screenshots
Main Production Screen

Main Production Screen

Facility Requirements

The facility requirements below are to be supplied by the customer at the installation site.

Electrical Power: 100-240 VAC / 50 – 60Hz / 1pH / 5 – 7.5 Amp
Inlet Air Connection: 3/4″ – 1.5″ FNPT based on configuration
Pressure Range: 70 – 120 psig
Temperature Range: 60° – 90°F
Particulates: < 5 microns
Oil Content: < 10 ppm
Pressure Dew Point @ >100 psig: < 39°F

Flow: Equal to the lesser of the maximum capacity of the flow bench or the requirement of the largest part for a 100% duty cycle. An air receiver will allow for maximum flow at less than 100% duty cycle.

Photos & Schematics

Additional Software Screenshots

The following are pictures and schematics of the Portable Air Flow Test Stand.

Portable Air Flow Test Stand being Calibrated

Portable Air Flow Test Stand being Calibrated

Portable Air Flow Test Stand with Workbench

Portable Air Flow Test Stand with Workbench

Portable Air Flow Test Stand inside Case

Portable Air Flow Test Stand inside Case

Portable Air Flow Test Stand, with connecting Sonic Nozzle and Meter Run

Portable Air Flow Test Stand, with connecting Sonic Nozzle and Meter Run


The following is a list of options available for this test stand:

  • Software customization including database integration, networking, SPC (Statistical Process Control) and more
  • Custom Fixturing Options
  • Compressors, dryers, filters and receivers
  • On-site installation, training, commissioning and upgrades
  • Heat exchangers and Dewpoint alarm
  • Silencers
  • Flow Computer: FC175

System Check Standards

The following optional additions are available to monitor the ongoing system accuracy and can also be used to diagnose problems: