EPA CFR part 1065 Compliance

On-board PM measurement for real-world results

OBS-ONE PM unit is the industry-leading on-board Particulate Matter (PM) measurement system. It collects PM on a filter paper, using a partial flow gravimetric sampling method, while simultaneously measuring real-time PM. A key feature of this design is the use of a venturi flow meter which enables
reliable proportional sampling and accurate exhaust gas flow measurement under transient flow conditions. Combine the GAS unit and PM unit to perform certification tests on heavy duty and non-road vehicles.


For Certification

  • US EPA CFR part 1065 subpart J
  • Simplify data collection and post-processing regulation requirements by using this measurement method

For R&D

  • Easily compare in-lab test results with real-road test results
  • Support R&D by simulating real-world driving events in the test cell with the Test Automation System STARS

◎ The world’s smallest PM measurement system in its class*

     *As of July 2015. Based on our company's research.

  • Easily mounted on any vehicle (modular and front access design)
  • One-touch fitting for module and cable connections

◎ The reliable test method for high speed flow rate control

  • PM transient measurement by proportional sampling

◎ User-friendly design mounts easily on any vehicle
    (modular and front-access design)

  • One-touch fitting for module and cable connections
  • Cartridge filters are easily changed 

Integrated Operation Software

OBS-ONE and other HORIBA ONE series measurement devices employ a common interface with future expandability. Control and management of each emission measurement device can be integrated into a single controller, as well as provide notifications of system health.

Manufactured by HORIBA


Measuring Principles

Batch sampling : Filter gravimetric method
Real-time PM measurement : Diffusion charging method

Measuring Ranges (Real-time PM sensor)

0 to 2500 mm/cm3 (Concentration after dilution)

Dilution Method

Partial flow dilution method (Proportional sampling mode / Fixed dilution ratio mode)

Signal for Gas Sampling

Exhaust gas flow rate : Isolated analog signal (0-10 V)

Flow Rate of Diluted Gas

10 to 15 L/min (Under the conditions of 20 deg.C and 101.3 kPa)

Filter Holder

Diameter 47 mm, Effective diameter 26.2 mm (Without backup filter)

Particle Pre-classifier (Cyclone)

99% penetration of particle size of less than 1 μm
50% cut off point : particle size between 2.5 and 10 μm

Power Requirements

DC 24 V

Power Consumption

Max. 0.6 kVA


350(W) x 470(D) x 460(H) mm (Excluding controller and protruding objects)


Approx. 45 kg (Excluding controller)

Operating Conditions

Temperature : 0 to 40 deg.C (During operation)
Relative humidity : less than 80%  Altitude : 0 to 2000 m above sea level

System Configuration

Combination of PM measurement unit and GAS measurement unit