ORTEC DSPEC Pro, Руководство пользователя по оборудованию

Страница: 13 / 108

794380D / 0914 1. INTRODUCTION
3
Patent number 5,872,363.
4
Patent number 5,912,825.
5
Ron Jenkins, R. W. Gould, and Dale Gedcke, Quantitative X-Ray Spectrometry (New York: Marcel Dekker,
Inc.), 1981, pp. 266–267.
3
Sample Changer Connections and Controls The DSPEC Pro connects easily to many types
of automatic sample changer.
Compact, Convenient Connectivity A small footprint means that the DSPEC Pro can sit right
on the desktop. Lightweight but rugged, multiple units can be stacked on top of one another via
their interlocking cases without fear of sliding or tipping. The easy-to-read, backlit LCD screen
displays the instrument ID, name, preset count conditions, current live and real time, dead-time
percentage (if active), input count rate, HV status and value, and, the serial number of SMART-1
detectors.
Use a USB hub to quickly connect multiple instruments to your computer. ORTEC C
ONNEC
-
TIONS
software supports any combination of USB devices (to a total of 127) connected to a
particular computer. In addition, any number of other ORTEC multichannel buffers (USB and
other interfaces) can be connected to the same system.
Standard DSPEC-Family Features The DSPEC Pro also offers the InSight™ Virtual Oscillo-
scope, which allows you to optimize detector performance for a given application from the com-
puter; our easy automatic pole-zero adjustment
3
and automatic baseline restorer
4
; and the highly
accurate Gedcke-Hale extended live-time correction method.
5
1.2. Enhanced Throughput Mode
To optimally process an input pulse stream, and thereby obtain the best spectral resolution, the
signal processing device should allow the input signal to return to baseline before beginning to
process the subsequent pulse. However, in cases where some loss of resolution is acceptable, it
is possible for a DSP to begin processing a subsequent pulse before the first pulse has returned
to the baseline, provided the first pulse has returned to baseline when the peak-detect of the
second pulse occurs.
The ORTEC Enhanced Throughput Mode takes advantage of this feature of digital signal pro-
cessing by allowing you to adjust the delay between the peak-detect and the start of processing
of the next pulse. The dead time for a conventionally processed pulse is the sum of the pulse’s
rise time, flattop, and fall time. By contrast, the dead time in ORTEC’s Enhanced Throughput
Mode can be as little as the rise time plus the flattop. These two scenarios are illustrated in
Fig. 1. The DSPEC Pro lets you set a protection time (PT), following a peak-detect, that blocks