Automotive Mass Air Flow Sensor (MAFS) Test Stand: Fully AutomatedProduct Summary

The fully automated version of the Automotive Mass Air Flow Sensor (MAFS) Test Stand is an air flow measurement system designed for setting and measuring the mass flow rate of through Mass Air Flow Sensors and other induction components.

Key Features
  • Mass flow range: 0.00098 – 1.5 lbm/sec (0.5 – 694 gps) ±0.4% of reading
  • Highly repeatable results (less than ±0.25%)
  • Lowest uncertainy and highest automation of the three Mass Air Flow Sensor Test Stands
How does this test stand work?

This test stand utilized sophisticated controller software which allows for automated test sequencing of mass flow measurement of air mass flow rate, MAFS voltage or frequency and ambient test conditions (P, T and RH) from a pre-configured array of set points. The system utilizes sonic nozzles which are installed in a common plenum and the test setup is shown in the following diagram:

Related Products for Varying Levels of Automation & Uncertainty

For information on related test stands, refer to the Mass Air Flow Sensor Test Stand Product Comparison.

Optional configurations for throttle body/chamber and cylinder head testing are available upon request. For more information about customized versions of this test stand, read about the Intake / Exhaust Manifold and Cylinder Head test stand, which was a custom test stand designed to meet specific customer specifications.

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

The fully automated version of the Automotive Mass Air Flow Sensor (MAFS) Test Stand has the following specifications:

Specification Value(s)
Mass Flow Rate 0.00098 – 1.5 lbm/sec, ±0.4% of reading
0.8 – 1225 scfm, ±0.4% of reading
0.5 – 694 gps, ±0.4% of reading
1.6 – 2498 kg/hr, ±0.4% of reading
Flow Measurement Gas Flow Calibrator
Repeatability Less than ±0.25%, defined as 2 standard deviations divided by the mean of 20 samples
Unit Under Test (UUT) Voltage 0 – 5 VDC, ±0.02% Full Scale
0 – 10 VDC, ±0.02% Full Scale
Unit Under Test (UUT) Frequency 0 – 20 kHz, 50 ppm
Unit Under Test (UUT) Pressure 0 – 15 psia, ±0.02% Full Scale
Unit Under Test (UUT) Differential Pressure 0 – 60″ H2O (Optional)

Uncertainty Analysis

For information on uncertainty analysis for this equipment refer to Uncertainty Analysis in Gas Flow Measurement When Using Sonic Nozzles.


Software

National Instruments LabVIEW Logo
Control System Operator Interface

This test stand uses the Gas Flow Calibrator for mass flow measurement and flow control. The system controller software manages and measures flowrates bases on user-defined test plans. These test plans are used to control flow rate by adjusting the configuration of the internal sonic nozzles. Controller software is written using National Instruments LabVIEW™.

Create Flow Rate Test Plans Specifying a Variety of Parameters
  • Flow rates can be measured in: mass rate, actual volumetric rate, standard volumetric rate, pipe Reynolds number, throat Reynolds number, pressure range or dp range
  • Reading can be taken for: pressure, temperature, frequency, voltage and current
  • Values such as number of points, time between points, flow direction, etc. can be specified
  • Test plans can be run repeatedly
Report Live Data and Compare to Historical Data
  • On-screen tabular and graphed results displayed in real-time
  • Live data can be plotted against previous data for historical analysis
  • Variety of user-customizable reports
  • Allows the operator to read all system sensors, and 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
Specify Settings for When Data Points Are Recorded
  • “Last Match”: The user records a data point, then configures the system so that future data points must be within a specific percent difference from the original data point
  • “All Data”: All data points are recorded– there is no filtering based on user or system defined parameters
  • “All Within Limits”: The user enters the parameters (temperature, pressure, flowrate, etc.) that define a valid data point, then the system only records a sampling of data points that fall within these parameters
  • “Averaging Length”: The system records all data points taken for a user-defined time limit
Configure Instrument Calibration Settings
  • Calibration coefficients for instruments connected to the Gas Flow Calibrator (i.e. pressure transducers, RTD’s, and dew point transmitters) can be generated then saved to file, which can then be associated with instruments
Determine Average Value & Repeatability of Master/System Unit Under Test
  • Measures the repeatability, average and percent difference (measured and calculated) of a series of consecutive flow tests through a master Unit Under Test
  • Performs test stand audits by measuring the repeatability, average and percent difference of a calibrated master sonic nozzle against the installed system nozzles
System Accuracy Check
  • Measures the repeatability, mass flow and percent difference of a calibrated master sonic nozzle against one or more installed system sonic nozzles
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
  • 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
Calibration Profile Configuration

Calibration Profile Configuration

Graphing Configuration

Graphing Configuration

Main Production Screen

Main Production Screen

Report Configuration

Report Configuration

View Data Point Details

View Data Point Details

Data Graphing Tool

Data Graphing Tool

Instrument Calibration Coefficients Entry

Instrument Calibration Coefficients Entry

System Exerciser (troubleshooting utility)

System Exerciser (troubleshooting utility)

Facility Requirements

The following facility requirements, which are to be supplied by the customer at the installation site, are needed for all three versions of the Automotive Mass Air Flow Sensor (MAFS) Test Stands:

  • Shop Air: 5scfm, 70 to 120 psig, 60 to 90°F; Pressure Dewpoint < 39°F; Particulates: < 5 microns; Oil Content: < 10ppm
  • Electrical Power: 100-240 VAC / 50 to 60 Hz / 1pH / 7.5 to 15 A
  • Vacuum: 2114 acfm at 12.3″ Hg based on previously defined mass flow range

Photos & Schematics

Additional Software Screenshots

The following are pictures and schematics of the Automotive Mass Air Flow Sensor (MAFS) Test Stand: Fully Automated Model.

General Arrangement Drawing

General Arrangement Drawing

Front View

Front View

Back View

Back View

Back View Close-Up

Back View Close-Up