TSI Instruments 3082, Operation And Service Manual

Page: 184 / 225

B-2 Electrostatic Classifier Model 3082 and SMPS Spectrometer Model 3938
In 1989, Wang and Flagan improved upon the system by using a
dynamically scanned DMA voltage. This system, called SEMS (Scanning
Electrical Mobility Spectrometer) , provided rapid aerosol distribution
measurements. Instead of requiring several intervals of ten minutes each
to measure a size distribution, the SEMS could provide results in less than
one minute.
In 1993, TSI commercialized the scanning system as the SMPS™
spectrometer.
In January of 1999 TSI began shipping a complete redesign of earlier
Classifier models as the Model 3080 with modular DMAs. The instrument
included improvements over the previous model including:

Choice of two interchangeable DMAs and flexibility to use custom
DMAs.

Recirculating flow for precise match of sheath and excess flows (a
great improvement over the 3071).

Microprocessor-controlled volumetric flow.

Front-panel design with control knob and built-in display.

Precision dynamic high-voltage supply for fast, accurate scanning.

Optional easy-to-install positive high-voltage supply (negative supply is
standard).

Electronic control of flow, voltage, particle-size, and instrument
functions.
In September 2013 TSI began shipping a redesign of earlier Classifier
models as the Model 3082. The instrument retains all the functionality of
the 3080 with improvements such as:

Dual polarity DMA high voltage control with <50ms response time for
faster scanning.

50 Hz data sampling for higher time resolution.

30 L/min sheath flow capability for higher size resolution and wider
size range.

Integrated and removable x-ray bi-polar charge neutralizer.

Integrated and removable inlet impactors for aerosol flow
measurement and particle pre-separation.

Tool-free installation of DMAs and impactors.