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Flex200R is a high-speed real time digital correlator.
It has two modes of operation.
Flex200R in single correlation mode specifications:
- Auto/cross correlations.
- 12.5 ns minimum sample in single correlation mode
- 288 real time channels in single correlation mode.
- Delay time range: 12,5ns to 1 hour in multiple tau channel layout.
- Input signal: standard TTL pulses.
- Two BNC connectors
- Easy to use FlexWindows software and software for Windows NT 4.0 and Windows95/98
libraries included.
Multiple tau channel layout ( sample time denoted at T, data width W) single mode:
- First 16 channels: T = 12.5ns, W = 1 bits, delay times T to 16*T;
- Second 8 channels: T = 2*12.5ns, W = 2 bits, delay times 9*T to 16*T
- Third 8 channels: T = 4*12.5ns, W = 3 bits, delay times 9*T to 16*T;
- Fourth 8 channels: T = 8*12.5ns, W = 4 bits, delay times 9*T to 16*T;
- Sample time doubles every 8 channels and data width increment 1 bit to prevent overflow.
- The longest delay time is about one hour.
Intensity limits:
Flex200R is designed with sufficient hardware resource to prevent overflow at any
reasonable intensities. However, in extreme situations, clipping and overflow could
happen.
The intensity in single mode limits are following:
- Maximum intensity integrated over 12.5 ns: 80 MHz. Clipping will occur if the
input intensity exceeds the maximum.
- Maximum intensity integrated over 100 ms: 28.28 MHz. Overflow will happen if the
maximum is exceeded.
Flex200R in dual auto correlation mode specifications:
- Two auto correlation functions.
- 160ns Minimum sample time.
- 2x272 in dual correlation mode.
- Delay time range: 160 ns to 1 hour in multiple tau channel layout.
Multiple tau channel layout ( sample time denoted at T, data width W) dual mode:
- First 16 channels: T = 160ns, W = 3 bits, delay times T to 16*T;
- Second 8 channels: T = 2*160ns, W = 4 bits, delay times 9*T to 16*T
- Third 8 channels: T = 4*160ns, W = 5 bits, delay times 9*T to 16*T;
- Fourth 8 channels: T = 8*160ns, W = 6 bits, delay times 9*T to 16*T;
- Sample time doubles every 8 channels and data width increment 1 bit to prevent overflow.
- The longest delay time is about one hour.
Intensity limits:
The intensity in dual mode limits are following:
- Maximum intensity integrated over 160 ns: 43.75 MHz. Clipping will occur if the
input intensity exceeds the maximum.
- Maximum intensity integrated over 338 ms: 12.5 MHz. Overflow will happen if the
maximum is exceeded.
More about multiple tau theory.
Multiple tau theory was invented by Klaus Schätzel. The following papers discuss
the theory and the advantage of the multiple tau scheme.
- Klaus Schätzel. Single Photon Correlation Techniques. Dynamic Light
Scattering: The method and some applications, Edit by Wyn Brown, Clarendon Press, Oxford,
P 76, 1993.
- Klaus Schätzel et. Noise on Multiple-Tau Photon Correlation Data.
SPIE Vol. 1430, P109, Photon Correlation Spectroscopy: Multicomponent Systems,
1991.
- Klaus Schätzel. New Concept in Correlator Design. Inst. Phys. Conf. Ser. No.
77, P175, 1985.
- Klaus Schätzel et. Photon Correlation Measurements at Large Lag
Times. Journal of Modern Optics, Vol. 35, No. 4, P711, 1988.
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