Quad-Track Diffusion Dryer
The Quad-Track Diffusion Dryer was designed to produce dry stable aerosols. The Dryer has four aerosol paths, each one encapsulated in desiccant beads, in a cylindrical body. The end caps are machined with NPT (National Pipe Thread) fittings for connecting the aerosol line fittings. This effectively lengthens residence time and the efficiency of the diffusion process is enhanced by increasing the available surface area of the desiccant. Comparison tests between the Single-Path and Quad-Track diffusion dryers have been conducted using three types of nebulizers. Filter samples collected from upstream and downstream locations relative to the Quad-Track Dryer showed there were minimal particle losses as a result of sedimentation, diffusion or impaction. The results of this test are detailed in "Design and Evaluation of the Lovelace Quad-Track Diffusion Dryer".

Lovelace Aerosol Nebuliser

This compressed air Nebulizer system may be used as an aerosol source for a variety of testing and research purposes. It is found in widespread laboratory uses for aerosolizing liquid solutions and suspensions. Water and other fluids have been used as solvents or suspension media. The nebulizer is one of the most efficient nebulizers commercially available.

The nebulizer operating characteristics are described in the table below. The nebulizer is fabricated from a clear acrylic (cup) and a tooling compound (top). The jet is acrylic, however, it is also available in Delrin, Brass or Stainless Steel. The nebulizer is sealed between the cup and top with a neoprene O-ring.

A Nebulizer Control Unit is also available.

  Air Pressure (PSIG)

1. Nebulizer air flow in liters per minute
2. Rate of liquid atomization in microliters per liter of air
3. Rate of water evaporation in microliters per minute
4. Rate of water evaporation in microliters per liter of air
5. Degrees centigrade at equilibrium
6. Degrees centigrade
7. Volume median diameter in micrometers
8. Droplet size distribution geometric standard deviation

 

High Output Aerosol Nebuliser

The High Output Aerosol Nebulizer is designed to fulfill the need for an aerosol source operating with several cubic feet per minute of compressed air. Most often used in conjunction with large whole body inhalation exposure chambers, it is also ideal for generating test aerosols to characterize high volume sampling systems.
Body and baffle are lucite, jet is brass and exit system is stainless steel.

Nebuliser operating conditions are listed below. 

Technical Specifications

Air Pressure (psig)

	30 psi	40 psi	50 psi
Air Flow Rate (1)	25	32	38
Total Aerosol Output (2)	32	36	32
Evaporated Water Output (3)	8.5	6	7
Reservoir Temperature (4)	10	9	9
Room Temperature (5)	23	23	23
Droplet Diameter (6)	6.1	6.1	6.1

In-Line Filter Holders

An in-line filter holder holds either a 25 mm or 47 mm filter, depending on the model, in a fixed sample line. Filters are the primary standard used for determining aerosol concentration. Filters collect particulates by interception, inertial impaction, and diffusion as the aerosol is drawn t

An in-line filter holder holds either a 25 mm or 47 mm filter, depending on the model, in a fixed sample line. Filters are the primary standard used for determining aerosol concentration. Filters collect particulates by interception, inertial impaction, and diffusion as the aerosol is drawn through them. The sample flow rate is a calibrated flow. Filters are weighed before and after sample collection. The weight differential is determined: post sample weight – pre sample weight. The volume of air sampled is calculated: sample flow rate x sample time. The quotient of differential weight and sample volume is the mass per unit volume aerosol concentration. Sample weight differential can also be determined by chemical analysis rather than gravimetrically.

Passive Air Filter

A passive air filter is usually a type of HEPA (High Efficiency Particulate Absorption) filter that is positioned in the aerosol delivery line of an inhalation exposure system. It is used on negative pressure system to allow passive or negative pressure flow to enter the system. The filtered air acts to dilute and dry the aerosol. A passive air filter also acts as a pressure buffer and enables steady maintenance of chamber pressure and easy, rapid adjustments. In positive pressure systems it acts to scrub particulates out of the air stream before it exits the system.

Solubility Filter
Solubility filters are used to determine the solubility of different compounds. This is useful for the drug discovery and chemical industry researchers. They are used to determine solubility of test articles and vehicles. Basically, the test article is put into a solution and passed through the filter. Whatever is left behind on the filter is the insoluble fraction.

7 Stage Cascade Impactor

In-Tox Products' Impactors are precision engineered and their careful design provides a number of advantages to the user. The material collected on each stage contains particles having sizes ranging from the cutoff size of the previous stage to the cutoff of the collecting size. Therefore, the analysis of the impactor data may be done without complicated computer programs. It also means that the particles collected on one stage can be re-suspended and used as an aerosol with known size particles. 

The precision design and fabrication of the I.T.P. Impactor means a lower wall loss of particles. Typical losses for our impactors are less than 10%. The low loss design is also important to the accurate uniform performance of the impactor. This design allows the air flowing through the impactor to establish the proper flow pattern after passing through one stage before entering the next. 

In-Tox Products Cascade Impactors exhibit the sharpest aerosol particle cut-off efficiency curves of any commercially available design. Our cascade impactors can be operated over a range of flow rates without sacrificing collection efficiency. 

Mercer Style

Standard Impactor Sizes

Multi-Jet

Standard Impactor Sizes

Cyclone

The In-Tox Products Cyclone Train is used to determine the particle-size distribution in process streams and to bypass the limitation of Impactors. Cyclone Samplers are advantageous for collecting large samples and in sampling aerosols of high particulate concentration. Cyclones are available in Brass or Stainless Steel and available with a Regular or Elongated Cup. The Cyclones may be purchase individually. A single Cyclone can be used as a pre-cut for a Cascade Impactor.

Diffusion Batteries

Serial Flow Diffusion Battery

The Serial Flow Diffusion Battery is most useful when determination of submicron particle number is important and when sampling from a stable aerosol source. This type of diffusion battery consists of a series of diffusion chambers placed one behind the other. Each stage provides a longer diffusion length than the stages in front of it. Aerosol is passed through the series of diffusion cells in a laminar stream. Particle penetration through each successive stage in the serial diffusion battery decreases. In order to determine how many particles pass through each stage, a particle counter such as the condensation nucleus counter is used to count the particles in a fraction of the air flowing through each stage. 

Parallel Flow Diffusion Battery

The Parallel Flow diffusion battery is useful in determining the mass fraction of submicron aerosols or when chemical and microscopic examination of collected submicron aerosol particles is important. This diffusion battery can be used with stable and unstable aerosol sources. This diffusion battery uses stages of increasing diffusion length, but provides for a different arrangement of the stages. In this device, stages of increasing diffusion length are placed parallel to each other. The instrument is arranged so that the same air flow rate passes through each stage or cell of the instrument and each cell samples the input aerosol. Behind each stage an absolute filter counter of similar optical system to count the number of particles passing each stage, the filters can be weighed or analyzed chemically to determine the mass of particles passing through each diffusion stage. 

Electrostatic Precipitators (ESP)

Combination Electrostatic Precipitator 

The Combination E.S.P. has two collection grids and uses an electrode like the Point-to-Plane model. It uses the same standard transmission electron microscope grid as one collection surface and a 3/8” carbon planchet as the second collection surface for scanning electron microscopy. By symmetrically placing the electrode and collection surfaces, the single needle electrode charges particles to both collection surfaces. The recommended current charge and flow rate is the same, 3 microamperes and 100cc/min., as with the Point-to-Plane.

Concentric Electrostatic Precipitator

The Concentric E.S.P. collects aerosol particles on a foil located inside of an aluminum column. The electrode is centrally located, in the air flow pattern, and with a high voltage corona discharged particles are deposited on the foil. The concentric E.S.P. can be used to collect samples for further analysis or as a cleanup device to extend the life of exhaust filters in an aerosol system. The Concentric E.S.P. can be operated at flow rates up to 125L/min. thus allowing it to be used to sample large air volumes. Although sample collection efficiency may vary in different situations, suggested operating current is 25-30 micro amps. Average collection efficiency for dry particles should exceed 80%. 

Point-to-Plane Electrostatic Precipitator

The Point-to-Plane E.S.P. has a single grid collection surface. It uses the standard transmission electron microscope grid as a collection surface. When operated at a current of 3 microamperes, and an aerosol flow rate of 100cc/min. the collection efficiency exceeds 90% for particles down to 0.01 microns diameter. 

Impinger

The Impinger is an instrument used to collect aerosol particles. Aerosol particles are sampled at a known, constant flow rate into a known volume of liquid. Solid particles are counted to determine aerosol concentration. Concentration of liquid or dissolved particles can be determined by chemical analysis.

Virtual Impactor

Conventional cascade impactors have been used extensively for fractionating airborne particles according to their aerodynamic sizes, enabling the size distribution to be determined by analyzing the collected particles. This technique has sometimes created problems, including stage overloading and particle re-entrainment.

The Virtual Impactor does not collect particles, but merely redirects them into two different air streams according to the cutoff characteristics. The same principle of inertial separation is used, but the impaction plate is replaced by a region of relatively stagnant air contained in the cavity of a receiving probe. The fine particles follow the streamlines of the major air flow, while the coarse particles pass into the forward minor flow region. Both particle size groups can, subsequently, be ducted for any desired methods of analysis or collection. This instrument is generally free from particle bounce and re-entrainment that often occurs in other size separating samplers.