DNP Series — Defined Nano Particle Aerosol Generators

DNP Series — Defined Nano Particle Generator for Calibration of Particle Measurement Instruments

DescriptionDNP 2000

The calibration of particle measuring devices should be conducted with particles being similar to the actual aerosol to be measured concerning shape, size, density, surface characteristics and refractive index, as for example with measurements of diesel soot emissions from vehicles.

Designed to generate well defined particle sizes, the DNP Series consists of two models DNP 2000 and DNP 3000 for the generation of test aerosols similar to diesel soot with an adjustable particle size distribution of approx. 20 nm - 150 nm at mass flows of up to approx. 6 mg/h.DNP 3000

Regulation (EC) No 715/2007 for type approval of motor vehicles Euro 5 / 6, identifies that particulate emissions should be measured using instruments which have been calibrated in accordance with guidance from the UN/ECE's Particle Measurement Program (PMP), which recommends the particle size to be adjusted to 30 nm, 50 nm and 100 nm for the calibration of the complete measuring chain. The DNP 2000 and DNP 3000 produce a particle spectrum from which the 30, 50 and 100 nm particle fractions can be separated with a DEMC (Differential Electro Mobility Classifier).Size Distributions of agglomerates at different spark frequencies

The generation principle relies on a flashover or spark, generated between two graphite electrodes placed close together with a high voltage difference applied between the two. These electrodes are placed in a flow of nitrogen and as the spark is generated, the graphite evaporates and then re-condenses to form nano particles in the gas flow, which agglomerate to form clusters further along the transport flow path.

As the voltage difference is maintained constant and the distance between the electrodes is maintained accurately, the energy converted by each spark remains constant and a stable particle distribution can be achieved. The addition of mixed air can be used to dilute the produced aerosol and therefore the agglomerates formed.

The two models operate on the same principle, with the DNP 2000 having manual and mechanical adjustment of settings and the DNP 3000 adding mass flow controllers and a touch screen PC for the control of the instrument. The DNP 3000 therefore allows parameters and settings to be saved and recalled for automated standardised testing protocols.

Technical parameters

  • Particle material: carbon
  • Carrier gas: nitrogen
    • Volume flow: 4 - 6 l/min
    • Primary pressure: 4 bar
  • Dilution gas: particle-free and dry compressed-air
    • Volume flow: 0 - 40 l/min
    • Primary pressure: 4 - 8 bar
  • Number concentration: > 107 Particles/cm3
  • Mass flow: approx. 0.06 - 6 mg/h
  • Particle size:
    • Primary: 3 - 5 nm
    • Agglomerate: approx. 0 - 150 nm
  • Operating time: several hours non-stop
  • Dimensions (WxHxD): 470 x 125 x 435 mm
  • Weight: 23 kg
  • Power supply: 115/230 V ; 50/60 Hz

Application examples

  • Determination of separation efficiency of media for diesel soot filters
  • Inhalation experiments
  • Toxicology

Particular advantages

  • Very good short-term and long-term constancy of particle size and concentration
  • Fast adjustable particle size distribution
  • Particle structure similar to diesel soot
  • Easy handling
  • Reliable function
  • Best reproducibility
  • Low maintenance

Please contact us for more detailed information.