Fluke Victoreen 451P, Operator'S Manual

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General Information
Introduction
1
1-1
Section 1
GENERAL INFORMATION
1.1 Introduction
The Model 451P Ion Chamber Survey Meter is a hand-held,
pressurized, battery operated unit designed to measure gamma and
x-ray radiation above 25 keV, and beta radiation above 1 MeV, using
the latest CMOS and LCD technology. The 451P case is constructed
of high strength ABS plastic. A gasket seals moisture out of the unit
and provides a cushion for the internal components. The Model 451P
readout consists of a 2 1/2 digit liquid crystal display and a 100
segment analog bargraph. The bargraph contains a zero segment
and twenty groups of five segments each. A permanent scale is
located on the display screen. The major divisions of the scale
indicate the units corresponding to the range that the meter is
measuring. Units of measurement are displayed next to the 2 1/2
digit display. LOW BAT and FREEZE will appear on the display when
the instrument is operating in these modes. External controls consist
of an ON/OFF button and a MODE button. The unit is auto-ranging
and auto-zeroing and has an auto ON backlight. The backlight
automatically comes on when the ambient light conditions fall below
twilight levels. An internal factory set alarm will blink the display if the
rate exceeds 5 R/hr. Two 9-volt batteries, located in the rear of the
instrument, provide over 200 hours of continuous operation.
1.2 Features
1.2.1 Overrange Rate
If the instantaneous radiation rate measured by the Model 451P exceeds 5 R/h, the 'R' in 'mR/h' or the
'Sv' in 'Sv/h' displayed will blink to notify the user that a potential error in the integrated radiation value
exists. The blinking will stop when the integrated value is cleared. This, however, may also clear the log
data RAM.
Model 451P & 451P-DE-SI
Ion Chamber Survey Meter