Too fast to measure? Losing valuable data because your digitizer is too slow?
You can now take a single waveform one millisecond long . . . . measure it in 1024 one microsecond increments with five-bit accuracy . . . . and store it in a fast memory . . . . all in 1.024 milliseconds! No other commercially available device can digitize and store this much data this fast. For waveforms of 2 to 16 milliseconds duration the Digitizer also has selections of 2, 4, 8, and 16 microseconds per data point interval. Of course, longer duration waveforms can be measured directly with the Fabri-Tek signal averager. And if your waveform is repetitive, measurement accuracy increases with the number of measurements made. The High Speed Digitizer memory stores the results of each fast waveform measurement. After each waveform measurement the Digitizer automatically reads out the recorded data at a rate of 50 microseconds per point to a Fabri-Tek signal averager. The averager may be used as a data storage and readout device for single waveform measurements. When repetitive signals are measured, the readout from the Digitizer is algebraically added into the signal averager memory. The averager then functions as an accumulator as well as a display and readout device. When a repetitive fast signal obscured by noise is measured, the averager accumulates and averages the data to reduce the noise in addition to providing display and readout.
The Fabri-Tek high-speed digitizer system is
During the readout to the averager the D i g i t i z e r is not measuring the signal, but this "dead time" is not critical since it occurs after each signal. System efficiency for repetitive signals is essentially 100% in cases where the signal occurs at a rate of 15 times per second or less. Where fewer than 1024 data points per signal are needed, lossless operation occurs at correspondingly faster repetition rates. The ability to distinguish small differences in signal amplitude is called "resolution." Five-bit resolution would sometimes be too low except for the fact that, after several measurements, the presence of noise on the input signal tends to improve signal resolution. For cases where the input signal noise is absent, a controlled systematic "noise" is introduced in the High Speed Digitizer. This controlled systematic "noise" is introduced at fixed intervals, in fixed steps, to continuously improve vertical statistical accuracy. This accuracy increases as a function of the number of measurements taken; for example, if at least 32 measurements have been made, the vertical resolution is one part in 1024.
FTi
FT-952 High Speed Digitizer "•sut.
Instrument Division Post office Box 4218 5225 Verona Road Madison, Wisconsin 53711 Telephone (608) 238-8476 FT-1052 Signal Averager Circle No.
40 on Readers' Service Card
VOL 39, NO. 4, APRIL 1967
·
25 A
