ORTEC Micro-Detective-HX, Руководство по эксплуатации

Страница: 18 / 96

ORTEC Micro-Detective
®
-HX Human Portable Radiation Detection System — Operation Manual
5
Nominal; the real-time duration of these spectra may at times exceed 1 second.
8
2.4. Overview of Radiation Monitoring and Measuring
2.4.1. How the HX Collects and Analyzes Data
!
Once the HX cools down to operating temperature, the HPGe detector high voltage
automatically turns on, and data collection and analysis begin.
!
The HX monitors for radiation at all times and on all screens. With the exceptions noted in
the next bullet, it collects one spectrum per second,
5
and analyzes a rolling window of the
eight most recent 1-second spectra for radioisotope identification and alarms, based on the
nuclide identification library in Appendix B. The spectra acquired in the Home [passive
monitoring] mode are only monitored for alarms, not saved.
!
In the Survey mode, the HX continues acquiring 1-second spectra and analyzing a rolling
window of the eight most recent 1-second spectra for IDs and alarms. In addition, the
summed spectrum for each rolling window is saved to the Survey’s ICD1 file. You can also
optionally acquire Long Samples and Fixed Samples, longer-duration spectra that are also
analyzed for alarms in real time. In Long Samples, a single spectrum is acquired for
30 seconds or more, and is analyzed once per second for alarms. Fixed Samples are treated
similarly but have pre-set durations of 5, 10, 15, 20, 25, 30, 60, 120, or 300 seconds. These
Long and Fixed spectra are also saved in the ICD1 file. In addition to these spectra, the HX
simultaneously collects a cumulative spectrum for the entire Survey, which is analyzed for
alarms and recorded at the end of the measurement as described below.
!
When radiation is detected and identified, the identification is posted to the real-time
identification area of the screen. This area lists the names of any radioisotopes currently
being detected and their classification as a threat (T) or innocent (I). In the standard
identification mode, all IDs are at high confidence. Only the expert LCX mode generates
suspect (S) and low-confidence IDs.
!
For each identification, the corresponding alarm is posted in the message area at the bottom
of the screen (refer to Fig. 1). You must press or tap the S button once to acknowledge (and
silence) each alarm before you can perform the next operation. When multiple alarms are
generated, the highest-priority (i.e., highest threat level) alarms are presented first.
Section 2.5 describes the color and LED scheme for each type of alarm.