Product Specifications
The CM11 Contamination Monitor is
designed for radiation workers to
monitor themselves, their clothing
and belongings effectively after a
minimum of training and supervision.
It has the versatility of advanced
portable monitors without complexity.
Easy-to-use and versatile personnel
contamination monitor
The dual channel
CM11 operates with
a large range of
sensitive probes
Easy to use correctly:
No user controls or
adjustments, clear
displays and
annunciators, direct
Slim profile with
suitable fixtures for
mounting to a wall, a
personnel monitor or
the bench
The CM11 is effective as an add-on
device to personnel monitors to
increase monitoring throughput rates.
This contamination monitor also works
well as a monitoring station during
temporary work such as plant
maintenance. The CM11 is ideal where
space is restricted. It is easy to install
and to set up, and equally easy to
assign to the next application.
The CM11 is ideal as a backup
boundary monitor; to confirm Personnel
Monitor alarms, to pin-point the
position of contamination and amount
per 100 cm2, to differentiate radon
nuisance alarms from others and for
use in an emergency or when AC
supplies are down. Monitoring
applications arise within power and
fuel handling sites, also defense
establishments, government
laboratories and hot labs in hospitals
and industry.
Thermo Fisher Scientific’s different
versions, CM11A to CM11F, carry
hangers for the 20, 50, and 100 cm2
scintillation probes and the DP11 gas
flow probe. The following types of
radiation may be monitored:
- α, β, simultaneous
- α plus β,
- low energy gamma
- simultaneous 125I and β.
System Specifications
Background is measured and stored until
the proximity sensor is tripped or the probe
lifted from the hanger, when monitoring
starts. Background is then subtracted from
the counts before they are displayed. The
peak hold feature makes it easier to
pinpoint spots of contamination, and their
levels, by simultaneously displaying the
peak and instantaneous readings.
Results are shown on a log scale ranging
from 0.2 to 10 alarm levels, and on a digital
display in units of countrate, total activity or
specific activity. The two readout channels
are normally configured for alpha and
beta/gamma, but can be configured to
separate 125I from beta/gamma when used
with the GP13 low energy gamma probe.
Versions in which the probe window faces
out allow hands to be monitored before
actually touching the probe.
Special Performance Features
- Radon recognition algorithm - eliminates
nuisance alarms by distinguishing radon
alarms from others.
- Gas flow and scintillation detectors both
use a standard coaxial cable.
- Signal processing for smoother displays of
changing countrate with better detection
of contamination.
- Internal power source gives at least 2.5
hours operation without main power.
- Operating point can be set by cursor from
graphic display of plateau.
- Built-in routines; high voltage scan,
plateau plot S plus B and S2/B values for
probe characterization.
- Gas flow rate and pressure are monitored
by electronic means.
- Passive infra-red proximity sensor, or
footswitch (optional), allows hands to be
monitored before touching the probe.
QA Features
- A continuous self-test program prevents
monitoring of invalid or fault conditions
- The probe can be tested for contamination
after each measurement.
- Selectable count-averaging times and
confidence levels on the alarms.
- Data recording possibilities; peak readings
for each measurement, setup parameters
and HV scan results (using the serial port
and an external printer).
Typical Applications
- Monitoring clothing in parallel with
hand/foot monitors to speed up
- Monitoring items next to an IPM or PCM.
- Detection of radon nuisance alarms.
- With a DP6 or DP11 probe, to quantify and
pinpoint IPM/PCM alarms from diffuse
contamination that pancake geigers
cannot detect.
- As a temporary monitoring station.
- A workstation or exit monitor in a small
- As a subchangeroom monitor.
- As a specialized monitor for low energy γ
- To provide monitoring for feet, identity
cards, laundry, tools etc. in combination
with special probes.
Display Units: cps, cpm, Bq*, dpm*,
Bq.cm-2*, nCi* (*Probe efficiency and
area are entered during setup).
Alarm Levels: 0.1 to 100,000 display units.
Display Channels: α, β/γ, α plus β/γ, 125I
plus β/γ.
Monitoring Update Time: 0.1 to 10 s.
Background Update Time: 10 to 100 s.
User Control: Removal of probe from hanger
(or triggering optional proximity sensor
activates measurement cycle with back
ground subtracted. Replacement of probe
causes resumption of background
Display: CCFL backlit LCD, resolution 240 x
128 pixels. Digital, bargraph and graphic
display. Timed count rate, timed
disintegration rate, HV scan and plateau
Audible Indications: Distinct tones for
particle detected, alarm and fault
Printout: Peak results, parameter settings
and HV scan results.
External Printer: Any RS 232 serial printer.
Temperature Range: 5 to 40 °C, (41 to 104 °F)
operational -10 to 50 °C (14 to 122 °F)
during storage.
Humidity: Up to 95% RH.
Power: 85 to 264 VAC, 74 to 63 Hz, 40VA.
Dimensions: 240 x 380 x 160 mm approx.
(9.5” x 15” x 16.5”)
DP11 Gas Flow Probe used with CM11F
Technical Specifications
Sensitive Area: 150 x 67 mm (100 cm2).
Window: 0.9 mg.cm-2 aluminized mylar.
Efficiencies: (% surface emission, 100 cm2
source) 241Am, 32%; 14C, 38%; 60Co,
49%; 137Cs, 58%.
Gamma Response: 40 cps (approx.) in a uniform
field of 1 mSvh-1 (100 mRh-1 due to 137Cs).
Gas: Ar/CH4, 90/10 % to 95/5 % proportion.
Control: Built-in control/cut-off valve and
electronic flowmeter.
Consumption: 1.5 liters/hour (25 cc/minute)
Options and Accessories Include
Proximity Sensor, Footswitch, IPM mounting
kit, Bench mounting kit,Trolley for CM11
and gas bottle, Gas bottle kit, Large area
check sources
Please note: Probe, cable and accessories
are ordered as separate items. For
assistance in selecting the appropriate
items, please contact our sales staff.
©2007 Thermo Fisher Scientific Inc. All rights reserved. Kapton is a registered trademark of of E.I. du Pont de Nemours and Company. All other trademarks are the property of Thermo Fisher
Scientific Inc. and its subsidiaries. Results may vary under different operating conditions. Specifications, terms and pricing are subject to change. Not all products are available in all countries.
Please consult your local sales representatives for details. Literature Code LITCM-11 0407
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