Fluke Victoreen 451P, Victoreen 451P-DE-SI Operator's Manual

Victoreen®

451P & 451P-DE-SI

Ion Chamber Survey Meter

Manual No. 1020101000 Rev. 2
©2004, 2005 Fluke Corporation, All rights reserved. Printed in U.S.A.
All product names are trademarks of their respective companies

February 2005

Operators Manual

Fluke Biomedical

Radiation Management Services

6045 Cochran Road
Cleveland, Ohio 44139

440.498.2564

Table Of Contents

Section 1: General Information

1.1 Introduction .................................................................................................. 1-1

1.2 Features....................................................................................................... 1-1

1.3 Receiving Inspection.................................................................................... 1-2

1.4 Specifications............................................................................................... 1-2

Section 2

2.1 External Controls ......................................................................................... 2-1

2.2 Installation.................................................................................................... 2-2

Section 3: Theory Of Operation

3.1 Introduction .................................................................................................. 3-1

3.2 Firmware...................................................................................................... 3-2

Section 4: Maintenance

4.1 Introduction .................................................................................................. 4-1

4.2 Routine Cleaning ......................................................................................... 4-1

4.3 Storage ........................................................................................................ 4-1

4.4 Battery Replacement ................................................................................... 4-2

4.5 High Voltage Battery Board Replacement ................................................... 4-3

4.6 Replacement Parts Information ................................................................... 4-3

4.7 Recalibration and Service Information ......................................................... 4-4

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Operation

..................................................................................... 2-1

................................................................................. 4-1

...................................................................... 1-1

...................................................................... 3-1

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General Information

Introduction

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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.

Model 451P & 451P-DE-SI
Ion Chamber Survey Meter

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.

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Victoreen 451P & 451P-DE-SI

Operators Manual

1.2.2 Low Battery Indicator

There are about six hours of operation remaining when the LOW BATTERY indicator first becomes
visible. When the LOW BATTERY indicator blinks, there is less than one hour of operation remaining.
These times are for two batteries installed and from the first occurrences of these indications. If the
instrument is turned off during a low battery condition, the batteries will recover somewhat, but time of
operation remaining will be less. The LCD low battery indicator is disabled during communication mode.
Be sure to use fresh batteries when calibrating this instrument.

WARNING

If chamber bias is LO, the instrument can’t measure
high radiation rates accurately. Service to the
instrument is required.

Verify the chamber bias is low. Turn the unit off and replace with new 9-volt batteries. Power up the unit.
After the self-test, if blinking low battery reoccurs the bias is low. Refer to Section 4 Maintenance.

1.2.3 Warm-up Time

The pressured ion chamber collection potential is 105 Vdc and is derived from the 5 lithium cells. The
warm-up time for an instrument that has been off 12 or more hours is about four minutes for readings less
than 20 μR/h in a 10 μR/h or less background.

1.3 Receiving Inspection

Upon receipt of the unit:

1. Check the shipping cartons(s) and their contents for in-shipment damage. If damage is evident, file
a claim with the carrier and contact Fluke Biomedical, Radiation Management Services Repair
Coordinator at 440.498.2564 or 800.850.4606 immediately.

2. Check that all items listed on the packing slip are present and in good condition. If any items are
missing or damaged, contact Fluke Biomedical, Radiation Management Services Repair
Coordinator at 440.498.2564 or 800.850.4606 immediately.

1.4 Specifications

Radiation Detected Beta above 1 MeV & gamma above 25 KeV

Operating Ranges 0 to 500 μR/hr (0 to 5 μSv/h), 0 to 5 mR/h (0 to 50 μSv/h)

0 to 50 mR/h (0 to 500 μSv/h), 0 to 500 mR/h (0 to 5 mSv/h)
0 to 5 R/h (0 to 50 mSv/h)

Accuracy ± 10% of reading between 10% and 100% of full-scale indication on any range,

exclusive of energy response (calibration source is

137

Cs)

Detector 230 cc volume air ionization chamber, pressurized to 6 atmospheres

Plastic chamber wall 200 mg/cm2 thick

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General Information

Specifications

Warm-Up Time Less than one minute for initial operation when the instrument is in temperature

equilibrium with the surrounding area and about 4 minutes for readings less than
20 μR/h in a 10 μR/h or less background

Drift After seven minutes operation, 0.04 mR/h equivalent, or less

Response Time Time measured from 10% to 90% of final value for a step increase/decrease in

radiation rate such that a range change does not occur:

0 to 500 μR/h (0 to 5 μSv/h) range: 5 seconds
0 to 5 mR/hr (0 to 50 μSv/h) range: 2 seconds
0 to 50 mR/h (0 to 500 μSv/h) range: 1.8 seconds
0 to 500 mR/h (0 to 5 mSv/h) range: 1.8 seconds
0 to 5 R/h (0 to 50 mSv/h) range: 1.8 seconds

NOTE: In pulsating field, the instantaneous rate should not exceed 5 R/h for

proper integration; instantaneous exposure rate is still limited to 5 R/h

Precision Within 5% reading

Readout Liquid Crystal Display: contains an analog bar graph with a permanent scale on

the display and a 2 1/2 digit display

Analog Display: the bargraph consists of 100 segments, 2 ½ inches long; the

scale has five major divisions; the appropriate value for the operating range of
the instrument will appear below the scale

Digital Display: the digital display is 2 1/2 digits followed by a significant zero

digit depending on the operating range of the instrument. The leading 1/2 digit is
blank, or a “1” or a “0” for clarity. Units of measure appear to the right of the
digital display. Appropriate multipliers also appear on the display

Units: as indicated under Range, programmable in R/h or Sv/h. Appropriate

multipliers also appear on the display

Auto-On Backlight: turns on when ambient light is less then twilight conditions

1

External Controls ON/OFF button, MODE button

Automatic Features Ranging and zeroing are fully automatic.

Environmental Operating Temperature Range: - 4º to + 122ºF (- 20º to + 50ºC)

Relative Humidity Range: 0 to 100%, non-condensing

Geotropism: less than 1%

Dimensions 8.5 (l) x 4.5 (w) x 8.6 in (h) (21 x 11.4 x 21.3 cm)

Weight Approximately 2.6 lb (1.2 kg)

Batteries Two 9-volt batteries provide over 200 hours continuous operation

* Specifications are subject to change without notice.

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