Automotive Emissions Monitor - 3433i

The Automotive Emissions Monitor 3433i is a highly accurate and reliable Multi Gas Monitor based on the INNOVA 1314i platform with special configuration for Exhaust Gas or SHED Evaporative Testing.

Its measurement principle is based on the photoacoustic detection method. In addition to its high sensitivity for multiple trace pollutant monitoring, the model 3433i is valued for its extremely simple integration into most test installations and for enabling reliable direct measurements.

Automotive Emissions Monitor - 3433i
Automotive Emissions Monitor - 3433i Seitenansicht


  • Automotive SHED Evaporative Emissions (SHED Testing): Measurement of Methanol, Ethanol, Toluene, Carbon Dioxide, and Freon R134a (or other refrigerant)
  • Vehicle Exhaust Emissions: Monitoring of Ammonia, Ethanol, Nitrous Oxide, Carbon Dioxide, and Carbon Oxide

Key Features

  • Multi Gas Monitoring – up to 5 different gases (+ water vapor) can be measured with excellent sensitivity and accuracy
  • Linear response over a wide dynamic range
  • Highest stability (low drift) makes calibration only necessary 1-2 times a year
  • Extremely simple system integration needs with its direct sampling capability. No carrier gas is needed.
  • Accurate - compensates for temperature fluctuations, water-vapor interference and interference from other known gases
  • Self-test routines assure high reliability
  • Operates immediately: Virtually no warm-up time necessary

Other valuable product features include:

  • Three interfaces, USB, Ethernet and RS-232 for data exchange and remote control
  • Multiple user access levels, password protected
  • Swagelock gas connectors
  • PC software 7820, BZ7002 and BZ7003

Outstanding Gas Detection Limits Onboard

Gas selectivity is achieved through the use of optical filters with narrow bandwidth. By installing up to 5 optical filters in the INNOVA 3433i, it can measure the concentration of up to 5 component gases and water vapor in any air sample. Detection limit is gas-dependent, but is typically in the ppb region. The accuracy of measurements is ensured by the INNOVA 3433i's ability to compensate for temperature and pressure fluctuations, water-vapor interference and interference from other gases known to be present (Cross-compensation). Reliability of measurement results is ensured by regular, automatic self-tests.


The optical filters used in the instruments display different characteristics while sharing a basic design. Each filter comprises three separate infra-red elements; a narrow-band pass element, a short-wave pass element and a wide-band pass element. The narrow-band pass element has very specific transmission characteristics defined by the short-wave pass and wide-band pass elements, which prevents transmission of light at other wavelengths.

For any additional Software Download and Service Net of Automotive Emissions Monitor 3433i, please contact us .


Technical Data

Measurement Technique 
Photoacoustic infrared spectroscopy.
Measurement Specifications1
Detection Limit: Gas-dependent, but typically in the ppb region. Using the Gas Detection Limits chart, the detection limit for a selected sample integration time (S.I.T.) can be calculated.
Dynamic Range: Typically 4 orders of magnitude (i.e. 10,000 times the detection limit at 5 S.I.T.). Using two span concentrations it can be expanded to 5 orders of magnitude.
Zero Drift:

Typically ± Detection limit4 per 3 months1

Influence of temperature2 : +/- 10 % of detection limit4 /°C.

Influence of Pressure3 : +/-0.5 % of detection limit 4 /mbar.

Repeatability: 1 % of measured value1
Range Drift: +/- 2.5 % of measured value per 3 months1

Influence of temperature2 : +/- 0.3 % of measured value/°C.

Influence of pressure3 : -0.01 % of measured value/mbar.

Response Time
Is dependent on the Sample Integration Time (S.I.T.) and the flushing time defined. Please see the examples below:
Monitor-Setup  Response Times
S.I.T.: „Normal“ (5 s)
Flushing: Auto, (tube: 1 m)
One gas: ~27s
5 gases + water: ~60s
S.I.T.: “Low Noise” (20s) Flushing: Auto, (tube 1 m)  5 gases + water: ~150s
S.I.T.: “Fast” (1s)
Flushing: Chamber 4s,
Tube “OFF”
One gas: ~13s
5 gases + water: ~26s
Reference Conditions:
1 Measured at 20 °C , 1013 mbar, and relative humidity (RH): 60%. (A concentration of 100x detection limit4 was used in determining these specifications.)

2 Measured at 1013 mbar, and RH: 60 %.

3 Measured at 20 °C and RH: 60 %.

4 Detection limit is @5s S.I.T

Interference: The 3433i automatically compensates for temperature and pressure fluctuations in its analysis cell and can compensate for water vapor in the air sample. If an optical filter is installed to measure a known interferent, the 3433i can cross compensate for the interferent.
Pumping Rate: 30 cm3/s (flushing sampling tube) and 5 cm3/s (flushing measurement chamber).
Power Requirement: 100-240 VAC +/- 10%, 50-60 Hz.
Power Consumption: ~85 VA.
Total Internal Volume: The total Internal Volume of the measurement system: 60 cm3
Air Volume per sample:
Flushing Settings Volume of Air
Auto: Tube Length: 1m 140 cm3 /sample
Fixed time: Chamber 2s, Tube 3s 100 cm3 /sample
Fixed time: Chamber 2s,Tube “OFF” 10 cm3 /sample

Height: 175 mm (6.9 in).

Width: 483 mm (19 in).

Depth: 375 mm (14.8 in).

Weight: 14 kg (30.8 lbs).

The 3433i monitor uses three interfaces, USB, Ethernet, and  RS-232 port for data exchange and remote control.
Compliance with Standards
The 3433i has the following certifications:
  • CE-mark (for compliance with EMC and Low Voltage Directives)
  • NEMKO-mark (for compliance with UL and CSA standards)

The detailed Certificate of Conformity documents are available in our download section.

Optical filter configurations

The 3433i is typically configured with two different sets of optical filters depending on the type of application.

Automotive Exhaust Emissions

Gas Filter number
Ammonia UA0976
Nitrous Oxide UA0985
Ethanol UA0974
Carbon Dioxide UA0983
Carbon Monoxide UA0984

SHED Evaporative Emissions

Gas Filter number
Methanol UA0936
Ethanol UA0974
Toluene UA0981
Carbon Dioxide UA0983
Freon R134A UA0971


Check at our Detection Limit Charts for detailed definition concerning the optical filters and their spectral bandwidth.

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