Analytical Technologies Singapore

The Ludlum Model 329-32 Laundry Contamination Monitor is intended for automatic monitoring of both alpha and beta-gamma contamination on clothing or other light articles presumed to be free of radioactivity, or within release or reuse limits. A motor-driven steel-mesh conveyor belt carries articles between two gas proportional detector arrays. 

An audible alarm will sound when contamination exceeds the given alarm setpoint. A LED array spanning the belt shows the approximate position of the alarm on the conveyor, and provides the operator with the status of the machine. A dual LCD shows the counts and the current operating conditions, such as conveyor speed and gas flow. 

A security-code protected 20-key keypad also allows the changing of alarm set points, operating parameters, and other system information. The entire system is mobile, with lockable casters to prevent unwanted movement of the monitor.

Each lower and upper detector array has 16 individual gas proportional detectors, providing 32 alpha channels and 32 beta-gamma channels for a total of 64 counting channels. A spare detector array (supplied with each system) allows for easy replacement, reducing down time. The detector arrays are staggered providing an even response across the conveyor. The usable detection width is 86.4 cm (34 in.) with an overall belt width of 91.4 cm (36 in.).

  • Highly Automated System
  • Simultaneous Monitoring of Upper and Lower Surfaces
  • Lockable Caster Wheels
  • 32 Alpha and 32 Beta-Gamma Channels
  • Audible Alarm is Accompanied by Visual Indicator LEDs for Indicating Approximate Location of Contamination
  • Real-Time Performance Status LEDs
  • Pass-Through Tunnel Adjusts Up to 17.8 cm (7 in.) Height
ApplicationClothing and light article scanning
System Control PanelTwo 40-character wide by 8-line LCD displays with back lights and 20-key control pad (provides count readings for each channel as well as system parameter information and control)
Detector ArraysTwo arrays (one on top, one on bottom), each of sixteen 100 cm2 (15.5 in2) gas proportional detectors in two staggered rows of eight, providing a 86.4 cm (34 in.) wide continuous detection area
Spare ArrayA spare array is stored under unit and connected to gas for quick replacement if necessary.
Recommended Counting GasP-10 (10% methane, 90% argon)
Detector Window0.4 mg/cm2 aluminized polyester
Array Area (each)Active~ 2000 cm2 (310 in2)
Open~ 1600 cm2 (248 in2)
Efficiency (4π)90Sr/90Y~ 22%
High VoltageAdjustable from 200 to 2500 V
ThresholdAlpha125 mV
Beta-Gamma2.5 mV
Beta-Gamma Window50 mV
Background UpdateCan be done manually or automatically when no articles are on conveyor belt
Count TimeAdjustable from 1 to 12 seconds
Article SizeMaximum 17.8 x 86.4 cm (7 x 34 in.) (W x H). Upper conveyor adjustable from 0 to 17.8 cm (0 to 7 in.) above lower conveyor.
Automatic Re-ScanFeature allowing for automatic reverse and re-scan of articles when alarm is indicated
Count Rate AlertAdjustable from 0 to 9999 cps (indicated by yellow lamp and LEDs on operator panels)
Count Rate AlarmAdjustable from 0 to 9999 cps (indicated by red lamp and LEDs on operator panels)
Audio2 unimorph-type speakers that are used to indicate the alarm conditions (greater than 68 dB at 0.61 m [2 ft])
AcknowledgePushbutton to silence audio
Serial PortAllows for output to printer
Conveyor BeltsTwo (one upper, one lower) 91.4 cm (36 in.) wide stainless steel woven mesh belts (80% open)
Conveyor SpeedAdjustable from 0.25 to 14 cm/s (0.1 to 5.5 in/s)
RunGreen pushbuttons on operator control panels and side of unit to start conveyor
StopRed pushbuttons on operator control panels and side of unit to stop conveyor
ReverseYellow pushbutton on side of unit to reverse conveyor
Emergency StopConveyor is encircled by pressure-sensitive bump bar to automatically stop conveyor when touched
Power95 to 135 VAC (220 VAC available)
ConstructionSteel frame and aluminum electronics housing
Temperature Range-15 to 50 °C (5 to 122 °F)
Size (H x W x L)150 x 116 x 282 cm (59 x 45.8 x 111 in.)
Weight250 kg (550 lb)
Shipping Size (H x W x L)152 x 122 x 301 cm (60 x 48 x 119 in.)
Shipping Weight568 kg (1250 lb)