BMD-1000

Overview

The Bag Mini-Diluter is an alternative to Constant Volume Sampling (CVS) Techniques and provides the improvements necessary to address the testing of Partial Zero Emission Vehicle (PZEV) and Super Ultra-Low Emission Vehicle (SULEV) emissions.  The differences between BMD and CVS sampling are as follows:

  • BMD is a partial flow sampler – about 6 lpm of vehicle exhaust is extracted.
  • Sample is diluted with zero air – eliminates problems with ambient bags having higher concentration than sample bags.
  • Dilution ratio is smaller – typically 5 to 1, making bag concentrations higher.

Features

The drawing shows the key components that make up a BMD system.  There are several critical factors for BMD accuracy that must be understood.  They are:

  • Accurate determination of critical flow venturi (CFV) flow-rates (dilution ratio).
  • Achieve sonic flow on the CFVs.
  • Maintain equal pressure and temperature for the sample and dilution CFVs.
  • Accurate measurement of tailpipe exhaust flow-rate.
  • Maintain proportionality of BMD bag fill flow-rate to tailpipe exhaust flow-rate (requires an accurate determination of gas transport delay time).

The BMD system contains the following provisions for minimizing the effects of contamination from impacting PZEV/SULEV test results:

  • Crinkle bags made from TFM (new material) which has improved THC out gassing and CO2 permeation characteristics compared to Tedlarâ or Teflonâ.
  • Semiconductor grade electropolished 316 SS plumbing (Ra<10).
  • Large radius tubing bends (10x diameter).
  • No viton elastomers.
  • Minimized internal volume in sample stream.
  • 5-stage purge sequence to sweep residual hydrocarbons from system.

Frow diagram

Manufactured by HORIBA

Specifications

1. System Outline BMD-1000 Specifications

Application

Alternative sampling technique to the CVS for gasoline-fueled PZEV/SULEV vehicles. Other fuel types to be evaluated.

Principle

Exhaust Sampling

Partial flow sampling method.

Constant ratio dilution method (using CFV)

Bag Sampling

Proportional to exhaust flow rate (using MFC)

 

Outputs

  • Monitoring on CRT
  • Saving on hard disk
  • LAN interface to test cell computer

Output Interval

0.1 sec (10 Hz data logging and communication)

Host Interface

LAN (Local Area Network), via Horiba MEXA-7000 Protocol

 

Exhaust Flow Rate Interfaces

Analog (0-10 VDC Scaleable) or Digital (Serial RS-232)

2. Configurations BMD-1000 Specifications

System Configuration

  • Main Unit - Oven, PC-based Controller, Heated sample line
  • Bag sampling unit

Connection of Piping

  • Exhaust Sample Inlet: heated line (70°C), ¼ in. tube fitting.
  • Diluent Gas Inlet: 3/8 in. Quick Connect fitting.
  • Cal. Gas Inlet: ¼ in. Quick Connect fitting.
  • Compressed Air Inlet: ¼ in. Quick Connect fitting.
  • Purge Gas Inlet: ¼ in. Quick Connect fitting.
  • QC Gas Outlet: 3/8 in. Quick Connect fitting.
  • Bag Bench Outlet: 3/8 in. Quick Connect fitting.
  • Vent Outlet: ¾ in. Hose.

Utilities

  • Diluent Gas: (Vehicle emission zero air) 40 liters/min at 60 PSI (414 kPa)
  • Cal Gas: (Typically CO2 in N2 blend used to check dilution ratio) 10 liters/min at 60 PSI (414 kPa)
  • Purge Gas: (Vehicle emission nitrogen) 40 liters/min at 80 PSI (552 kPa)
  • Compressed Air: 5 cc/min at 15 PSI (100 kPa)

Power Supply

120 VAC, 60Hz, single phase.

Power Capacity

(2) AC circuits (50 Amp and 20 Amp).

Dimensions
(W x H x D)

  • Main unit: 22.44 in. x 77.56 in. x 33.46 in.
    (570 mm x 1970 mm x 850 mm)
  • Bag Rack: 30 in. x 36 in. x 36 in.
    (762 mm x 914 mm x 914 mm)

Mass

Approx. 850 lbs (385 kg).

3. Function and Performance BMD-1000 Specifications

Dilution Ratio

±1% accuracy possible (verified NIST traceable calibration):

Dilution ratio range for Gasoline Fuel: 5.0 – 5.5

Dilution ratio range for Alcohol Fuel: 9.0 - 10.0

 

Proportionality

±10 %* sample bag fill proportionality to the exhaust flow rate signal (prior to correction for exhaust composition)

* not including engine idle conditions

Proportionality response

Typically 1.1 seconds total response time:

T90< 0.300 seconds for MFC plus gas transport time to Mass Flow Controller.

 

Exhaust Volume:

± 0.1 % integrated volume

Bag-Fill MFC Accuracy/Response

STEC 7450, 30 lpm FS, accuracy ± 1% FS, response time < 1 sec.

4. Operating Conditions BMD-1000 Specifications

Environment

  • In-door use only
  • Ambient temperature 60 to 90°F (15.5 to 32°C)
  • Relative humidity 10 to 85 %

Sample Gas Flow-Rate

  • Tailpipe exhaust extraction typically 6 lpm.
  • Diluent flow-rate typically 30 lpm.
  • Bag fill flow-rate varies from 0 to 30 lpm.

Sample Gas Conditions

  • Custom heated tailpipe probe furnished with the BMD.
  • Pancake filter protects sample CFV.
  • Oven temperature set for 70°C.
  • Tubing coils help ensure constant temperature at sample and diluent CFVs.
  • Diluent flow is controlled to maintain zero differential inlet pressure to sample and diluent CFVs.
  • Humidity sensor measures the % H2O of the diluted exhaust and corrects the CFV and MFC flow-rates.
  • Sample CFV flow-rate is corrected based on properties of the vehicle’s fuel.

Exhaust Line Conditions

Atmospheric pressure (acceptable variation at use within ± 1 kPa)

Related Products

CVS-7000

The CVS-7000 (Constant Volume Sampler) systems are used for measurement of mass emissions from all...

MEXA-7000 Version 3

An analyzer system designed for the continuous measurement of a wide range of exhaust gas...

STARS Engine

STARS was developed by the world class combination of HORIBA and Ricardo. STARS is a powerful,...

TITAN in Laboratory.

TITAN T

The design of the TITAN T Series is optimised for testing light and heavy-duty gasoline and diesel...

TITAN in Laboratory

TITAN D

The TITAN D Series extends the transient test opportunities to real dynamic test applications.