Eberline ESP-1 - SECTION IV. THEORY OF OPERATION; FUNCTIONAL THEORY

MODEL ESP-1
SECTION IV. THEORY OF OPERATION
A. GENERAL
The
ESP-1
employs
current
technology
to
provide
to
the
user
a
compact
instrument
that
can
be
used
to
measure
several
kinds
of
radiation
as
detected
by
different
detectors.
In
addition,
the
ESP-1
is
portable
and
will
operate
for
over
250
hours
before
battery
replacement
becomes
necessary.
The
instrument's
most
important
function
is
the
delivery
of
accurate
information
to
the
operator
efficiently
and rapidly.
B. FUNCTIONAL THEORY
The
ESP-1
consists
of
six
functional
sections
as
detailed
below
(see
figures
7-1, 7-2,
7-3).
1.
Detector
The
detector
connected
to
the
ESP-1
is
selected
to
optimize
its
output
for the
radiation
of
interest,
It
provides
the
pulse
signal
to
the
electronics
for
counting.
The
pulse
rate
from
the
detector
is
proportional
to
the
radiation-field
intensity
at
the
detector.
High-Voltage Supply
The
high-voltage
supply
provides
the
bias
voltage
to
the
detector
as
required
for
proper
operation.
The
high
voltage
is
adjustable
to
provide
the
correct
operating
voltages
for
a
large
selection
of
detectors
and
regulated
to
enhance
operating
stability.
Amplifier/Discriminator
\
The
amplifier
is
a
linear,
fixed-gain,
multistage
design.
It
amplifies
the
signal
from
the
probe
to
a
usable
level
at
the
amplifier
output.
The
discriminator
provides
a
signal
on
its
output
only
if
the
signal
from
the
amplifier
exceeds
its
adjustable
threshold.
This,
in
turn,
provides
a
means
for counting only the radiation signals and to reject any noise and/or unwanted signals.
Speaker/Alarm
The speaker/alarm section provides an audible "click rate" from the speaker, which is
proportional to the output of the amplifier/discriminator. This rate can be scaled down to
enhance the usefulness of the speaker when high-count rate (very sensitive) detectors are
employed. When the alarm is activated, the speaker emits a continuous 2000-Hz tone.
Microcomputer
The microcomputer is an eight-bit device programmed to function as the interface between the
ESP-1
operator
and
the
information
provided
by
the
radiation
detector
(probe).
Its
program
logic
and speed of execution allow the ESP-1 to be extremely versatile by applying mathematical
functions and logic to its input signals and displaying the results to the operator in an
understandable format.
ESP1.MAN/February
1992
4-1