Product Summary

Description

An Automobile Manufacturer required a test stand to measure the airflow leakage through a vehicle cabin in order to improve quality and reduce warranty expenses on wind, road and powertrain noise issues.

System Requirements

• Provide Pressure, Suction or Mass Flow Control within the Vehicle Under Test
• Measure Air Mass Flow Over a Wide Range (See Specifications for Ranges)
• User-Friendly Test System Controller
• Highly Reproducible Results
• Optional System Check Orifices
• Data Output Corrected to Nominal Day Conditions
• Custom Quick-Disconnect Fittings for Air Flow Hose, Filter and Check Orifices
• Software for Data Logging, Corrections and Storages
• HVAC, Fog and Air Heater Options

Solution

FLOW SYSTEMS designed and manufactured an Air Flow Metering System that employs a set of Bi-Directional Orifice
Plates. The Test Stand controls the pressure inside the vehicle as it undergoes leakage testing, and the pressure inside the vehicle body may be positive or negative with respect to the local barometric reading. The BLTS-4th Gen is designed to deliver a wide range of flow of air at an accuracy of +/- 0.8% of reading or better, with the maximum static pressure at the vehicle being +/-1000 Pa (+/- 4.0 inches H2O @ 4°C).

The Test Stand will allow the operator to easily change the flow direction. Indicators on the Operator Interface Panel display when the system is in either Pressure or Suction Mode.

The Test Stand includes System Check Orifices that allow for system verification. The test stand controller software includes the ability to set the flow at various rates and allow the operator to observe the percent difference between the check orifice and the test stand orfice meter reading.

System Specifications

Specification	Value(s)
UncertaintyEstimated to be better than 0.8% of reading with traceability to NIST standards.
RepeatabilityEstimated to be better than +/-0.5% as defined as 2 standard deviations divided by the mean of 20 identical samples
Cycle Time30 to 60 seconds depending on percent of maximum capacity
UnitsSLPS, Pa, °C (SCFM, In H2O@4°C, °F.)

UnitsSLPS, Pa, °C (SCFM, In H2O@4°C, °F.)

Connection Hardware From Test Stand To Vehicle
Pressure Line¼” OD poly tube 9 m long (30ft)
Hose Size9 m long (30ft). See table above for diameters

Built with Commercial Off-The-Shelf (COTS) Components

All Flow Systems air flow test system designs, the test system controller, data acquisition and control subsystems, and all instrumentation are standard and readily available Commercial Off-The-Shelf (COTS) items. This ensures that service or replacement of any item can be achieved in a timely manner, providing for high availability of our products. When applicable, this includes all of the Unit Under Test related instrumentation specified by the customer.

Comparison

Model	Flow Range			Pressure Range			Hose Sizes
BIP	1.5 to	75 slps	(3.2 to 159 scfm)	125 to	250 Pa	(0.5 to 1 “H2O@4C)	4” (100 mm)
G3	2.7 to	185 slps	(5.7 to 392 scfm)	125 to	250 Pa	(0.5 to 1 “H2O@4C)	6” (150 mm)
HVAC	0.5 to	284 slps	(0.1 to 600 scfm)	+ / –	250 Pa	( + / – 1 “H2O@4C)	8” (200 mm)
VOW	15 to	800 slps	(32 to 1695 scfm)	125 to	250 Pa	(0.5 to 1 “H2O@4C) suction	8” (200 mm)
				125 to	1000 Pa	(0.5 to 4 “H2O@4C) pressure

Traceable to NIST

All Flow Systems air test stands utilize sonic nozzles which have been calibrated and are traceable to National Institute of Standards and Technology (NIST).

Built with Commercial Off-The-Shelf (COTS) Components

All Flow Systems air flow test system designs, the test system controller, data acquisition and control subsystems, and all instrumentation are standard and readily available Commercial Off-The-Shelf (COTS) items. This ensures that service or replacement of any item can be achieved in a timely manner, providing for high availability of our products. When applicable, this includes all of the Unit Under Test related instrumentation specified by the customer.

Managed by LabVIEW™ Based Controller Software

Sophisticated Windows™-based controller software was developed by Flow Systems for test automation and data management using National Instruments™ LabVIEW™. Controller software can be customized to fit customer needs including integration with external database systems.

Software

The system controller software controls and records air flow to the vehicle cabin, then records the data to the specified data storage location.
Controller software is written using National Instruments LabVIEW™.

Functions

• Improved Vehicle Pressure Set-Point Adjustment
• Button for Data Logging
• Indication of Flow and Vehicle Pressure Stability
• Correction of Flow Test Data Based on Ambient Conditions, Test Pressure, Flow Mode and Nominal Day Conditions
• Data Record Organization with Comments
• Check Orifice Data Analysis
• Data Storage
• On-The-Fly Change Between SI and English Units
• Test Configuration
• Test Scripting
• Database for Test Results
• Data Record Organization with Comments
• Custom Database Mining Utilities
• Custom Report Functionalities

Additional Software Screenshots

Facility Requirements

VOW, HVAC, G3:
The facility requirements below are to be supplied by the customer at the installation site.

Electrical Power:
480 VAC/60Hz/3ph, 30 Amp

BIP:
120VAC/60Hz/1ph, 23 Amp

Photos & Schematics

Model	A = Length (bench)	B = Length (w/ elbow)	C = Depth	D = Height (w/ check orifice plenum)	E = Height (w/ check orifice plenum)	Ship Weight
BIP	52in / 1321mm	62in / 1575mm	46in / 1168mm	59.6in / 1513mm	75in / 1905mm	1,500lb / 680kg
G3	64in / 1626mm	78in / 1979mm	57.8in /1468mm	50.3in / 1278mm	67.9in / 1725mm	2,000lb / 900kg)
VOW/HVAC	84in / 2134mm	108.8in / 2762mm	66in / 1676mm	54.3in / 1380mm	80in / 2031mm	3,000lb / 1,360kg

Options

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

• Fog Machine ( Inject Oderless, Non-Staining Fog into Vehicle)
• On-Site Installation, Training, Commissioning, and Upgrades
• Auto Orifice Changer – Automatically Switches Test Stand Orifice Plates as Flow Demand Requires
• Air Heater (+10°C at 50 SLPS) for use with Thermal Camera
• Hardware & Software to Conduct HVAC Tests
• Plug & Play Instrument Calibration Panel
• Remote Estop Monitor, Keyboard and Mouse