TSI 100NR, 100S4, 110NR MOUDI Impactors

Description of TSI 100NR, 100S4, 110NR

These precision cascade impactors are designed for sampling and collecting size-fractionated particle samples for gravimetric and/or chemical analyses. The Models 100-R and 110-R Micro-Orifice Uniform Deposit Impactors (MOUDI™) both have a sampling flow rate of 30 L/min and are provided with an 18 μm cut-point inlet stage followed by additional stages to size-fractionate aerosol particle samples. The 8-stage Model 100-R has a lower cut-size of 0.18 μm while the 10-stage Model 110-R has a lower cut-size of 0.056 μm.

The MOUDI impactor differs from other conventional cascade impactors in the use of a large number of microorifice nozzles to reduce jet velocity and pressure drop, minimize particle bounce and re-entrainment, and enhance collection efficiency. As many as 2,000 nozzles with diameters as small as 50 μm are used. These impactors also have the uniform-deposit feature achieved by rotating the impaction plate relative to the nozzles so that the particle deposit under the nozzles can be spread out uniformly over a 25 mm diameter impaction area on a 47mm sampling substrate. The uniform deposit feature prevents heavy particle buildup under the nozzles to minimize bounce and re-entrainment. The mass of particles that can be collected without overloading can thus be greatly increased. Both the Models 100 and 110 are also available in non-rotating versions, Models 100-NR and 110-NR, with fixed nozzle and collection plates.

The MOUDI impactor is designed to size fractionate aerosol particles in four equal geometrical size intervals per decade of particle size. The stage cut-sizes would increase at a constant ratio of 101/4 =1.78 to 1.0. The nominal cut-sizes of the MOUDI Impactor stages are: 0.056, 0.1, 0.18, 0.32, 0.56, 1.0, 3.2, 5.6, 1.8, 10 and 18 μm.

Sampling Substrate and Stage Rotation—The MOUDI impactor can accept a variety of sampling substrates, including aluminum foils and 47mm diameter membrane filters. The substrate is held by a clamping ring on a substrate holder and is held by a magnet on the impaction stage (see diagram below). The substrate holder is easy to remove and replace. The collected samples can also be stored in a sample holder to prevent contamination during sample transport from the field to the laboratory or vice versa.

Applications

• Environmental air sampling for air pollution and air quality research
• Testing aerosol drug delivery devices
• Diesel blow-by size analysis
• Engine emission testing
• Automotive air bag testing
• Industrial hygiene studies
• Work place aerosol analysis

Features and Benefits

• Sampling flow rate
  • – 30 L/min
• Size interval and stage cut-size
  • Four equal geometrical increments per decade of particle size
  • Model 100: 0.18, 0.32, 0.56, 1.0, 1.8, 3.2, 5.6, 10, and 18 μm
  • Model 110: 0.056, 0.1, 0.18, 0.32, 0.56, 1.0, 1.8, 3.2, 5.6, 10, and 18 μm
• Sharp cut-point characteristics
• Low inter-stage particle losses
• Up to 2000 micro-orifice nozzles to reduce jet velocity and pressure drop
• Mechanically rotated stages to achieve uniform particle deposits and reduce particle bounce and reentrainment.

Technical specifications of TSI 100NR, 100S4, 110NR

Environmental Operating Conditions

• 10–50 °C (50–122 °F)
• 0%–90% RH (non-condensing)