The CM11 Contamination Monitor is designed for radiation workers to monitor themselves or other items being brought out of controlled areas for alpha and beta contamination. It's inherently user friendly design allows use with a minimum of training.
Product Detail
These multi-purpose, wall-mounted friskers are used with the DP11 gas flow probe or our scintillation probes. Extremely easy to use, features include proven microprocessor control, a graphics display, digital setup/calibration facilities and a durable housing. Variants can be supplied: e.g. mounted on a sack truck, or with large area detectors, or with multiple detectors - details on request.
Qualities
Peak and instantaneous readings both displayed
Radon Recognition feature reduces nuisance alarms
Plateau plot feature
Gas flow probes are supplied via a pipe alongside the MHV cable, or via a quick-release valve on the body of the monitor. With the valve option, no gas connection is required during frisking
Versatility: the dual channel CM11 operates with a large range of sensitive probes
Ease of Use: Clear displays and annunciators, direct readout, no user controls or adjustments
Compactness: 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 pinpoint 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. The CM11 design incorporates over 20 years of feedback from operational experience that has served to refine the specifications and add value. Better techniques are used to detect and indicate contamination. Setup has been greatly improved. Monitoring applications arise within power and fuel handling sites, also defense establishments, government laboratories, and hot labs in hospitals and industry.
Measurement
The different versions, CM11A-CM11F, carry hangers for the listed Thermo Fisher Scientific 20, 50, and 100 cm2 scintillation probes and the DP11 gas flow probe. The following types of radiation may be monitored:
Alpha, beta, simultaneous
Alpha plus beta
Low energy gamma
Simultaneous 125I and beta
Background is measured and stored until the proximity sensor is tripped or the probe lifted from the cradle, when monitoring starts. Background is then subtracted from the counts before they are displayed. A special dwell-on peak feature makes it easier to detect spots of contamination. The peak reading and the instantaneous reading are both displayed, making it easier to pinpoint the maximum reading after contamination has been detected.
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 with the probe window facing 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
Results displayed in count rate, total activity, or specific activity
Peak reading, displayed during measurement, makes it easier to pinpoint the maximum activity
Dwell on peak response assists in detecting small spots of contamination
Gas flow and scintillation detectors both use a standard coaxial cable
Signal processing for smoother displays of changing count rate with better detection of contamination
Internal power source gives at least 2.5 hours operation without main power
Graphics screen display far superior to mechanical and alphanumeric displays
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 monitored by electronic means
Passive infra-red proximity sensor (optional) allows hands to be monitored before touching the probe
QA Features
A continuous self-test program prevents monitoring of invalid or fault conditions are sensed
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 throughput
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 zone
As a subchangeroom monitor
As a specialized monitor for low energy γ radiation
To provide monitoring for feet, identity cards, laundry, tools, etc. in combination with special probes
Options and accessories include proximity sensor, foot switch, 1 PM 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.
cps, cpm, Bq*, dpm*, Bq/cm2*, nCi* (*probe efficiency and area are entered during setup)
Weight :
5 lb
Alarm levels :
0.1 to 100,000 display units
Display channels :
alpha, beta/gamma, alpha and beta/gamma, 125I and beta/gamma
Monitoring update time :
0.1 to 10 seconds
Background update time :
10 to 100 seconds
Display :
CCFL backlit LCD, resolution 240 x 128 pixels. Digital, bargraph, and graphic display. Timed count rate, timed disintegration rate, HV scan, and plateau plot
Display Indications :
Text and graphical display on LCD. "Alarm" and "Ready/Fault" LEDs.
Audible indications :
Distinct tones for Particle Detected, Alarm and Fault condition
Printout :
Peak results, parameter settings and HV scan results.
External printer :
any RS232 serial printer
Temperature range :
+5°C to +40°C, (41 to 104°F) operational -10 to 50°C (14 to 122°F) during storage
-10°C to +50°C during storage.
Humidity :
up to 95% RH
Power :
85 to 264V AC, 74 to 63 Hz, 40 VA
Dimensions (approximate) :
- Height :
240 mm
- Width :
380 mm
- Depth :
160 mm
User Control :
Removal of probe from hanger (or triggering optional proximity sensor) activates measurement cycle with background subtracted. Replacement of probe causes resumption of background measurements
DP11 Gas Flow Probe Used with CM11F Technical Specifications :
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