Contents xi
5 Technical Description .........................................................5-1
Theory...................................................................................5-1
Historical Notes.....................................................................5-2
Adiabatic Expansion CNC ..................................................5-3
Two-Flow Mixing CNC ........................................................5-3
Diffusional Thermal CNC....................................................5-3
Design of the CPC .................................................................5-4
Sensor................................................................................5-5
Microprocessor...................................................................5-7
Flow System..........................................................................5-7
High Flow...........................................................................5-8
Low Flow............................................................................5-8
Filters and Restrictors........................................................5-9
Flowmeter ..........................................................................5-9
Pump ...............................................................................5-10
6 Particle Counting.................................................................6-1
Optical Detection ..................................................................6-1
Single-Particle, Realtime Counting ........................................6-1
Total Count Accuracy............................................................6-3
Single-Particle, Live-Time Counting.......................................6-4
Photometric Calibration ........................................................6-4
Autoranging ..........................................................................6-5
7 Calibrating the CPC.............................................................7-1
8 Computer Interface and Commands...................................8-1
Computer Interface ...............................................................8-1
Pin Connectors...................................................................8-1
Baud Rate ..........................................................................8-2
Parity .................................................................................8-2
Computer Commands ...........................................................8-3
BASIC Program: TSICPC .......................................................8-6
9 Maintenance and Service....................................................9-1
Changing the Filters..............................................................9-1
HEPA Filter ........................................................................9-1
Tube Filter .........................................................................9-1
Pump Exhaust Filter (DQ) ..................................................9-4
Checking the CPC for Leaks ..................................................9-4
Installing an EPROM.............................................................9-6
Failures.................................................................................9-9
Technical Contacts..............................................................9-10
Returning the CPC for Service .............................................9-11