Atec Fluke-451B User Manual

451B

Ion Chamber Survey Meter with Beta Slide

The 451B state-of-the-art ion chamber survey
meter is a handheld battery operated unit
designed for use in both rugged and normal
environments. The 451B includes a sliding beta
shield to serve as an equilibrium thickness
for photon measurements and enables beta
discrimination. The 451B auto-ranges and
measures radiation rate and accumulated dose
from various radiation sources (alpha, beta, x-ray,
gamma). The ion chamber detector allows for
a fast response time to radiation from leakage,
scatter beams, and pinholes. Additionally, the
low-noise chamber bias supply provides for fast
background-settling time.

The digital display features an analog bar
graph, 2.5 digit readout, low battery indicator,
freeze (peak hold) mode indicator, and an auto­matic backlight function. User controls consist of
an ON/OFF button and a MODE button. The case is
constructed of lightweight, high strength materials
and is sealed against moisture.

The RS-232 interface can be connected directly
to a computer for use with the Excel add-in for
Windows (451EXL), enhancing the functionality
of the instrument. This software allows for data
retrieval, user parameter selection and provides a
virtual instrument display with audible and visual
alarm indication.

Technical Data

Key features

• Measures skin dose (slide open) and deep dose (slide closed)

• High sensitivity measurement of rate and dose simultaneously

• Records peak rate using “Freeze Mode”

• Auto-ranging and auto-zeroing

• RS-232 communications interface with optional Windows-based Excel add-in for

data logging

• Ergonomic, anti-fatigue handle with replaceable grip, wrist strap and tripod mount

• Programmable flashing LCD display

• Easily-accessible battery door (operated by two 9-volt alkaline batteries) on the

outside of the bottom case

• Available with dose equivalent energy response (SI units)

Specifications

Radiation detected Alpha > 7.5 MeV

Beta > 100 keV
Gamma > 7 keV

Operating ranges,
response time

Accuracy Within 10 % of readings between 10 % and 100 % of full scale indication on any range,

Detector Chamber (cc volume air

Automatic features Auto-zeroing, auto-ranging, and auto-backlight
Warm-up time One minute
Display LCD analog/

digital with backlight

Modes Integrate mode Operates continuously 30 seconds after the instrument

Environmental Temperature range -20 °C to 70 °C (-4 °F to 158 °F)

Typical energy
dependence

Power requirements Two 9 V alkaline, 200 hours operation
Dimensions (WxDxH) 10 cm x 20 cm x 15 cm (4 in x 8 in x 6 in)
Weight 1.11 kg (2.5 lb)

0 mR/h to 5 mR/h (8 sec)
0 mR/h to 50 mR/h (2.5 sec)
0 mR/h to 500 mR/h (2 sec)
0 R/h to 5 R/h (2 sec)
0 R/h to 50 R/h (2 sec)

exclusive of energy response

349 cc

ionization)
Chamber wall (phenolic) 246 mg/cm
Chamber window (mylar) 6.6 mg/cm
Beta slide 440 mg/cm

2

2

2

Analog 100 element bar graph 6.4 cm long. Bar graph is divided

into 5 major segments, each labeled with the appropriate
value for the range of the instrument

Digital 2.5 digit display is followed by a significant zero digit

depending on the operating range of the instrument. The
units of measurement are indicated on the display at all
times. Digits are 6.4 mm (0.25 in) high. Low battery and
freeze indicators are also provided on the display

has been turned on. Integration is performed even if the
instrument is displaying in mR/h or R/h

Freeze mode Will place a tick mark on the bar graph display to hold on

the peak displayed value. The unit will continue to read
and display current radiation values

Relative humidity 0 % to 100 % (at 140 °F)
Geotropism < 1 %

16

Nitrogen gamma rays are 110 % to 120 % of indicated readings as determined at the

University of Lowell

2 Fluke Biomedical 451B Ion Chamber Survey Meter with Beta Slide

1.2

Indicated/Actual

1.1

1

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

451B typical energy dependence

Effective (keV)

Side

Slide - Closed

Slide - Open

Ordering
Information

Models

451B -RY R Ion Chamber
Survey Meter with Beta Slide
and standard chamber

451B -RY R- S S Ion chamber
Survey Meter with molded grip
handle and shoulder strap

Optional accessories

451EX L 451 Assistant for
Excel, includes RS-232
interface cable

190 HPS Single Unit

00001000100101

Carrying Case
62 -10 3 Check Source,

137

Cs, 10 µCi. Flat disc,

1-inch diameter
450UCS Check Source,

238

Uranium, 0.064 µCi,
impregnated, 2 in x 2 in
yellow card

About Fluke Biomedical

Fluke Biomedical is the world’s leading manufacturer of quality
biomedical test and simulation products. In addition, Fluke Biomedical
provides the latest medical imaging and oncology quality-assurance
solutions for regulatory compliance. Highly credentialed and equipped
with a NVLAP L ab Code 200566- 0 accredited laboratory,
Fluke Biomedical also offers the best in quality and customer
service for all your equipment calibration needs.

Today, biomedical personnel must meet the increas ing
regulatory pressures, higher quality standards, and rapid
technological growth, while performing their work faster and more
efciently than ever. Fluke Biomedical provides a diverse range
of sof tware and hardware tools to meet today’s challenges.

Fluke Biomedical Regulatory Commitment

As a medical test device manufacturer, we recognize and follow certain
quality standards and certications when developing our products. We
are ISO 9001 and ISO 13485 medical device certied and our products are:

•  CE Certied, where required

•  NIST Traceable and Calibrated

•   UL, CSA, ETL Certied, where required

•  NRC Compliant, where required

3 Fluke Biomedical 451B Ion Chamber Survey Meter with Beta Slide

Fluke Biomedical.

Better products. More choices. One company.

Fluke Biomedical

6045 Cochran Road
Cleveland, OH 44139-3303 U.S.A.

Fluke Biomedical Europe

Science Park Eindhoven 5110
5692EC Son, The Netherlands

For more information, contact us:

In the U.S.A. [phone] or
Fax [phone]
In Europe/M-East/Africa [phone] or
Fax [phone]
From other countries [phone] or
Fax [phone]
Email: sales@flukebiomedical.com
Web access: www.flukebiomedical.com

©2007-2013 Fluke Biomedical. Specifications subject
to change without notice. Printed in U.S.A.
7/2013 3095534D_EN

Modification of this document is not permitted
without written permission from Fluke Corporation.