Real World Emissions Testing
Based on FTIR Technology

FAD
FAD‐‐RDE Workshop 2014
Ron Tandy
Acknowledgements (Data Provided By):
Hong Kong Environmental Protection Department
Carol Wong

Contents

 FTIR Technology Overview
 Features and Benefits of FTIR for Automotive and PEMS use
 FTIR Accuracy and Correlation (Real World Data) Conclusions

What is FTIR?
Multi‐component gas analyzer based onFourier Transform Infra‐Red technology.
Current FTIR technology allows for:• Continuous measurement of up to 40 gases• 5Hz data acquisition1.5sec)
5sec)• Fast response time (T10‐900 90 < 1
FTIR is the ideal instrument for• Engine development• Aftertreatment calibration• Catalytic converter
development

Typical FTIR System Configuration (Vacuum)
PC
Heated LineLAN

LAN

HeatedFilter

Communication
HubSpan Gas
Span / Audit
Gas Handling

Audit Gas

Purge / B.G.
N2 / Zero Air
Cell Pressure
Control

Heated Line

Sample110 VAC

LiquidN2

S tSpectrometertSampleConditioning

PowerConditioning

C diti i Unit
Conditioning
U it

Waste
120 VACor
24 VDC ** PEMS Version Onlyy

Spectrometer• The FTIR analyzer is an infrared
spectrometer, configured as adynamic multi‐component gasanalyzer• FTIR Technology uses aninterferometer, infrared light source,
heated gas cell (191 ° C) anda cooled infrared detector

Spectrometer• MKS 2030HS Spectrometer –16 micron, one‐half wave number
resolution (0.5CM‐1), LN2 CooledDetector

Interferometer Technology
Michelson Interferometer createsinterfering beams using:••••

IR Light source
Beam splitter
M i mirror
Movingi
Fixed mirror

A Helium Neon ((HeNe)) Laser
determines mirror position, velocityand travel direction

SampleCellThe output is a Interferogram,containing information about allwavenumber frequencies within the
mid‐infrared spectral range

Sample Gas CellInterferogram• Heated to 191
191° C
Prevents condensation
GAS• 5.1m Path
For high sensitivity• 200 mL cell volume
For fast response timeGAS

5.1 meter path (32 passes)

Frequency Absorption
Each molecule has a specific Infrared frequency where it
absorbs the IR radiation.
((Bending,di stretching,hi twistingi i , vibrating
ib i , etc. theh molecule)l l )Because of the constructive (and destructive) interferingbbeams,
th detector
thed t t can readd information
i fti aboutb t every
wavelength in the infrared range simultaneously.
The interfering beams travel through the sample gasgas, wheresome energy is absorbed by gas molecules and some istransmitted to the detector.
The transmitted portion (not absorbed) reaches thedetector.

Detector

The absorbed portion does not reach the detector, and isdirectly proportional to the amount of gas molecules in thepsample.

Interferogram to Gas Concentration

Interferogram

Single Beam

Signal as a function of time
(Position of Moving Mirror)

AbsorbanceSpectrumMethod Analysis

Signal as a function of frequency,(with reference)

Fourier Transform
algorithm

RemoveBackground
A= ‐Log(I/Io)

Spectrum Analysis• Method Determination(Gas, Diesel, CNG, Etc.)• Analysis of absorption regions• Speciation of gases

Conditioning Unit
• Communication and Control Spectrometer,PC, heated line & filter• Gas Handling
Zero and span gas regulation anddistribution, for calibrations, purging andb kbackgroundd• Cell Pressure Control
Controls the spectrometer cell pressure• Sample Conditioning
Cools sample and removes water (afterspectrometer, prior to pump and massflow meter)• Power Conditioning
Distributes power to spectrometer, HL, HF,and PC; accepts AC or DC (on‐board only)
input

PC

Cell Pressure Sampling
Vacuum Pressure• Vacuum
Vcontrolledt ll d cellll• Faster time response (T10‐T90 ~1.5 sec)
• Decreased consumption of exhaust gas

Atmospheric Pressure• Allows for the availability of standard
calibration
lib ti lib
libraries,i methods
th d andd hundreds
h d dof gases/ranges• Allows for easy integration
integration, of systems
already operating at atmospheric pressureVacuum Pressure Sampling

90 %AtmosphericMethod

10 %Vacuum pressure advantages:
Less gas degradation
degradation, decreased exhaust gas consumption
consumption, and significant reduction in the response timeSampling Rate
The FTIR spectrometer can sample at selectable rates, up to 5 Hz.
5 Hz sampling rates provide superior transient sampling, capturing more data
fluctuations than 1 Hz.

Messbare Gase•

Misst alle Gase die im mittleren
Infrarot Spektrumpabsorbieren•

Messung aller regulierten Gasesausser THC*

•Mehrere konfigurierbareMessbereiche (z.B. COLow and COHigh).

•Investitionssicherung
h‐ Erlaubtl b
Messungen von Gasen, die in derZukunft von Interesse sein könnten.

*THC is calculated (sum of HC’s) andbased upon a FID correlation factor

Gas
Formula
REGULATED COMPONENTS:
Carbon Monoxide (Low)
CO (L)
Carbon Monoxide (High)CO (H)
Carbon Dioxide (Low)
CO2
Carbon Dioxide (High)
CO2
Oxides of Nitrogen
NOX
Hydrocarbons
HC
NON-REGULATED COMPONENTS:
Nitrogen Oxide (Low)
NO (L)
Nitrogen Oxide (High)NO (H)
Nitrogen Dioxide (Low)
NO2 (L)
Nitrogen Dioxide (High)NO2 (H)
Nitrous Oxide (Low)
N2O (L)
NitNitrous
OOxideid (High)(Hi h)
N2O (H)
Ammonia
NH3Formaldehyde
HCHO
Formic Acid
HCOOH
Ethanol
C2H6O
Methane
CH4Methanol
MeOH (CH4OH)
Water
H2O
Acetaldehyde
MeCHO (CH3CHO)
Sulfur Dioxide
SO2Isocyanic Acid
HNCO
Hydrogen Cyanide
HCN
Carbonyl Sulfide
COS
DIFFERENTIATED HYDROCARBONS:
Methane
CH4Acetylene
C2H2
Ethylene
C2H4Ethane
C2H6Propylene
C3H6Propane
C3H8
1‐3 Butadiene
C4H6
IsobutyleneC4H8Butane
NC4 (C4H10)
Isopentane
C5H12Benzene
C6H6Octane
NC8 (C8H18)

ConcentrationUnits

0 ‐ 5000
ppm
0‐5%
0‐4%
0 ‐ 20%Calculated (sum of NO, NO2)
Calculated (sum of Carbons)
0 ‐ 300
0 ‐ 5000
0 ‐ 300
0 ‐ 1000
0 ‐ 100
0 ‐ 2000 ‐ 500
0 ‐ 1000

ppm
ppm
ppm
ppm
ppm
ppm
ppm
ppm

0 – 1000
0 ‐ 20000 – 1000
0 ‐ 300 ‐ 1000
0 ‐ 10000 ‐ 1000
0 ‐ 10000 ‐ 200ppm
ppm
ppm
%ppm
ppm
ppm
ppm
ppm

0 ‐ 2000
0 ‐ 10000 ‐ 10000 ‐ 1000
0 ‐ 10000 ‐ 10000 ‐ 10000‐5000 ‐ 10000 ‐ 2000 ‐ 500
0 ‐ 1000

ppm
ppm
ppm
ppm
ppm
ppm
ppm
ppm
ppm
ppm
ppm
ppppm

Evaluation by Regulatory Agencies
40 CFR Part 1065

System Response
40 CFR §1065.308

Linearity Verification
40 CFR §1065.307

Accuracy, Repeatability, Noise
40 CFR §1065.305

Meets or exceeds US EPA andEuro Regg 49 verification requirementsq(for regulated gases)

Interference Verification
40 CFR §1065.375

FTIR Customer Value
Measures up to 40 Gases

Factory calibration
remains stable during
life of the FTIRNo requirement fordaily gas calibrationsRequires almost nomaintenance, because
off it’s
i ’ simple
i l ddesigni
Much more reliable,compared to conventional
analyzers

Replaces multiple
conventional analyzers

St bilit
Stability

Reliability

Fl ibilit
Flexibility

Simplicity

Raw data files can be
reprocessed with amodified gas analysis
method. No need torepeat the test
Only one physicalanalyzer simplifies thewhole system
Only one delay time fordynamic analysis
No requirement
qfor
daily gas calibrations or
Linearizations

Customer Benefits• Secure Investment
Gases that might be of interest in the future can be
added without the need to integrate additionalanalyzers.
y• Low Total Cost of Ownership
Up to 40% lower operating cost compared toconventional analyzer systems due to less:• Maintenance• Operational work load (calibrations, diagnostics)• Required training• Span gas requirements• High Level of Flexibility
Can be utilized for many different applications andeasily be moved between different test locations.
• Excellent Correlation
With conventional gas analyzer systems.

Benefits of FTIR ‐ One Instrument
Replaces

Does Not Require

NDIR

CVS / Dilute

NDUV / CLD

Dry to Wet
Conversion

GC Instruments

Time Aligng Gas
Instruments

Impinger Systems

Daily Calibrations

Cutter FID

Linearization

Laser Diodeor QCL

Drift Correction

Correlation with Conventional Analyzers

Our testing shows FTIR
correlation is Approx. ±2%,when comparing toconventional analyzers(NO, NO2 , CO, CO2 , CH4)

Typical Applications (On‐Board)• Testing under Real‐World Driving conditions• Testing in harsh environments and high altitude• Catalyst Development• Evaluation of fuel additives without the need for a chassis
dynamometer• Correlation between test cell and real‐world test results• Emissions modeling in actual vehicle operational locations

PEMS FTIR Application

ProblemAC power availability

Solution

Road vibration

DC popowerer inlet (24V)
Vibration dampening system

Pressure changes (altitude)

Pressure control system

Weather conditions

Environment control box

g levelBatteryy chargeg indicator with alarmCharge

On‐Board Vibration Dampening

No deflection
Nd fl ti on th
the gas concentration,t tidduringi
G‐Force deflections from major road vibration

Typical FTIR PEMS Components
GPS Acquisition Unit and Software
Allows for GPS data (latitude, longitude altitude andspeed), to be recorded and time‐aligned with theemissions data.

ECU Acquisition Unit and Software
All
Allowsforf theth vehicle
hi l ECU datad t tot beb recorded
d d anddtime‐aligned with the emissions data.

Video Camera Monitoring System and Software
Allows for live on‐road video recording, time alignedwith emissions data, GPS and ECU vehicle data .

PEMS FTIR In‐Use

Hong Kong EPD On‐Road Testing Coach Vehicle
Tsing Yi – Stop & Go
7.14L Diesel
12 DEC 201212‐DEC‐2012
 Double Decker BusKowloon – Urban
10 8L Diesel
10.8L
08‐JAN‐2013“One of the most dense streets in the world”

In‐Use Hong Kong EPD Coach
Gaseous Measurement
A&D BOB‐1000FTBOB 1000FT and Sensors SEMTECH‐DS
SEMTECH DS
HK‐EPD Defendable Data Methods• SEMTECH‐DS: 1065 verification tests current• 1065 In‐use recommendations (e.g. drift corrections, etc.)• Linearity
Liit Verification,
V ifi tiSSpan(pre(andd post)t) andd 3‐hr
3h A
Audit’sdit’Hong Kong EPD Coach – NOX Data

FTIR Readings Slightly Larger• 5Hz (FTIR) vs 1Hz (DS) higher transient peaks• NDUV Chiller Loss (5% allowed per 1065.376)*SEMTECH‐DS wet (Calculated)Hong Kong EPD Coach ‐ NOX Data

Hong Kong EPD Coach – CO2 Data

Hong Kong EPD Coach – CO2 Data

Hong Kong EPD Coach – CO Data
CO peaks generally agree
but FTIR peaks are larger
Reasons:• 5Hz (FTIR) vs 1Hz (DS)(higher transient peaks)• FTIR high Range @ 4% CO• Peaks significantly above
NDIR‐DS Span Calibration
Value (200 ppm)

Hong Kong EPD Coach – CO Data

• At low concentrations CO follows same trend
g approximately
ppy ~50‐75ppm
pp lower• FTIR readings• Detection limit of DS‐NDIR ~ 50ppm

Amonia (NH3) Slip

FTIR can detect NH3 slip (SCR) when exhaust temperature drops

Hong Kong EPD Chassis Dynamometer Test Bed
Heat Exch.
Dilution Tunnel

CVS

BOB‐1000FTSEMTECH‐DS

ECOSTARCold Start Test 1

Warm Start Test 2

Cold Start Test 1

Warm Start Test 2

Cold Start Test 1

After evaluation, Hong Kong
EPD determined an issue
with the contractors
CVS/CLD system.
Hong Kong EPD is on record
stating that they believe thePEMS NOX is accurate, not
the CVS NOX (~ + 20%)

Warm Start Test 2

After evaluation, Hong Kong
EPD determined an issue
with the contractors
CVS/CLD system.
Hong Kong EPD is on record
stating that they believe thePEMS NOX is accurate, not
the CVS NOX (~ + 20%)

Climbing Mount Fuji

FTIR 25 Gas GraphMount Fuji Cylinder Gas

High Altitude Pressure Option
Maintains required Sample Cell
Pressure, regardless of changing
barometric pressure conditions.

Stable concentrations have been verified up
p to 3,200m,((11,000,feet))Conclusion
 FTIR Technology is a highly accurate method for exhaust gasmeasurementt
 FTIR technology
gy has manyy advantages
g over traditional PEMS andconventional analyzers
 FTIR has good correlation to conventional analyzers
analyzers, forregulated components, while also measuring all gases of interest– with one analyzer
 FTIR as a PEMS instrument will become increasingly important,as we continue to monitor and research additional gases,
gases andmore exotic gasses

Vielen Dank!