LUDLUM 70, Системное руководство

Страница: 9 / 35

Model 70 System Manual
Ludlum Measurements Inc.
2
May 2021
2. SYSTEM DESCRIPTION & FEATURES
This manual fully describes the system functionality of the unit along with the associated PC
software program.
2.1 OPERATIONAL FUNCTIONS
The Model 70 can be operated in two primary radiation monitoring functions.
1. Dose Mode – In this mode, the Model 70 acts as a radiation search/survey
meter displaying the current dose rate and count rate. A “chart-record” of the last 60
data points is displayed on the screen during the search. This mode is typically used to
search for radioactive material or to carry out total-count search. This mode also
displays the current dose rate up to user selection in Sv/h or in Rem/hr, as well as
cumulated radiation dose
from the time the mode was engaged. The dose meter is used
to determine the relative hazard level and to assess handling requirements of a
radioactive material.
The yellow line represents 20-second dose rate running average.
Visual, Audio, and Vibration mode alarms will be activated if the dose rate exceeds the
defined threshold.
2. Identify Mode – (Nuclide Identification) In this mode, the Model 70 accumulates
spectral data from a sample and analyzes the spectrum in terms of emitted energy and
net count contribution. The nuclides responsible for producing the spectrum are
identified by comparison to a nuclide library and presented in tabular form on the
screen. This essential information can then be used to determine the radiation risk to
the individual.
2.2 SYSTEM FEATURES
Instrument Body
– The instrument body consists of a single, rugged, plastic housing. The
housing has an option for the instrument to be mounted on a belt for ease of carrying during a
constant dose monitoring situation. In addition, included is a carrying case to carry and protect
the unit when not in use.
Detector
1. CZT – A 0.5 cm
3
or 1.6 cm
3
(optional) CdZnTe semiconductor hemispherical crystal is
used for the detection of gamma radiation and provides a high-resolution signal for the
systems nuclide ID capability. CZT is a specialized detector with a resolution several
times better than that of widely used inorganic scintillators (i.e Sodium-Iodide, Cesium-