Humidified Tandem Differential Mobility Analyzer

The Humidified Tandem Differential Mobility Analyzer (DMA) system has two differential mobility analyzers and a humidification section in between. Aerosol from the ambient atmosphere or from the built-in aerosol generator can be classified by the first DMA to produce a monodisperse aerosol for size analysis by the second DMA to determine the growth in particle size as a function of relative humidity.
 
Structure
 · Built-in Atomizer Aerosol Generator
· Electrical Ionizer
· Differential Mobility Analyzer (DMA)
· Electrical Mobility Spectrometer
· Condensation Particle Counter (CPC)
· Humidity Conditioner
· Data analysis software
 
Features
 · High stability atomizer aerosol generator
· High accuracy aerosol humidity conditioner
· Wide range, high resolution DMAs
· Patented dual-reservoir CPCs
· DMS and SMS data analysis software
· User friendly user interface with touch screen display
· Automatic data logging
 
Application
 · Study of the hygroscopic growth of aerosols for accurate deliquescence and efflorescence measurements. 
· Other aerosol studies by the TDMA method.
 
Technical Parameters

Overall Specifications of the Model 1040XP HTDMA*
Aerosol Generator (Part 1 of system)	460 mm (H) x 610 mm (D) x 525 mm (W)
Part 1/Part 2 Total Weight	100 lbs (45 kg)/ 140 lbs (60 kg)
Power Requirements (Part 1)	115 or 230 VAC, 50-60 Hz, single phase, 250 W max, 160 W steady
Humidity Conditioner/Spectrometer (Part 2)	460 mm (H) x 610 mm (D) x 525 mm (W)
Power Requirements (Part 2)	100- 240 VAC, 50-60 Hz, single phase, 500 W max, 400 W steady
Operating Aerosol Pressure	800 to 1050 mbar absolute pressure
Ambient Temperature Range	10 to 35 ºC
Ambient Humidity Range	0-90% RH, non-condensing

Polydisperse Aerosol Generation System
Single-Jet Atomizer	Stainless Steel Construction
Pressure	5 to 60 psig (5 to 415 kPa gage), controlled by manual pressure regulator
Aerosol Flow Rate	Typical 3 L/min @ 35 psig (240 kPa gage)
Volume Mean Droplet Diameter	about 2 µm (GSD< 2.0)
Aerosol Size Range	10 to 2000 nm
Aerosol Concentration	> 107 particles/cm3 (typical for NaCl)
Dryer	Diffusion type (NafionR membrane requires dry comp. air, -20 ºC dew point)

Humidity Conditioner
Relative Humidity Control Range	10 to 93% with user-selected set point in 1% intervals
Flow Rate	1 to 10 L/min
RTD and Dew Point Accuracy	± 0. 2 ºC
RH Accuracy	± 1.5% for chilled mirror sensor; ± 2.5% for capacitive sensor
RH control stability	± 1.2% (typical)
Response Time for < 10% ΔRH	< 3 min (typical)
Water Reservoir Heater Control	25 to 50 ºC in 5 ºC intervals
Saturator	Nafion® Humidifier with DI water closed loop circulation
Dryer	Diffusion type (Drierite® desiccant)