08354B DCN7877
Teledyne API T640 PM Mass Monitor
81
TECHNICAL ASSISTANCE
If this manual and its troubleshooting / service sections do not solve your problems,
technical assistance may be obtained from:
Teledyne API Technical Support
9970 Carroll Canyon Road
San Diego, California 92131-1106 USA
Toll-free Phone:
800-324-5190
Phone:
+1 858-657-9800
Fax:
+1 858-657-9816
Email:
Website:
http://www.teledyne-api.com/
Before contacting Teledyne API Technical Support, fill out the problem report
form in the Appendix, which is also available online for electronic submission at
under Technical Support Forms.
6.
PRINCIPLES OF OPERATION
The Model T640 PM Mass Monitor is an optical aerosol spectrometer that converts
optical measurements to mass measurements with sharp accuracy by determining
sampled particle size via scattered light at the single particle level according to
Lorenz-Mie Theory.
Briefly, the sampling head draws in ambient air with different-sized particles,
which are dried with the Aerosol Sample Conditioner (ASC) and moved into the
optical particle sensor where scattered light intensity is measured to determine
particle size diameter. The particles move separately into the T-aperture through
an optically differentiated measurement volume that is homogeneously illuminated
with polychromatic light. The polychromatic light source, an LED, combined with
a 90
°
scattered light detection achieves a precise and unambiguous calibration
curve in the Mie range, resulting in a large size resolution.
Each particle generates a scattered light impulse that is detected at an 85
°
to 95
°
angle where amplitude and signal length are measured; the amplitude (height) of
the scattered light impulse is directly related to the particle size diameter.
The T-aperture and simultaneous signal length measurements eliminate border
zone error, which is characterized by the partial illumination of particles at the
border of the measurement range.
Summary of Contents for T640
Page 2: ......
