AN IONIZATION CHAMBER LAUNDRY MONITOR

Technical Report · Sun Jun 01 00:00:00 EDT 1958

OSTI ID:4275908

Chester, J D; Handloser, J S

The determination of the amount of contamination remaining on a garment after it has been washed is an important part of hot laundry operations. In the past garments were monitored by measuring the contamination concentrated in the crotch with a GM tube probe. This type of spot check does not detect any isolated hot spots on other pants of the garment. To monitor the entire garment with a GM tube instrument is excessively time consuming for a large number of garments. To overcome these difficulties a sensitive, large-volume ionization chamber was constructed. It is rectangular in shape, 5 ft high by 2 1/2 ft wide by 4 in. deep. The center electrode is of a grid type and is mounted halfway between the front window and the back of the chamber. In a 0.5-mr/hr field, 180 v is sufficient to saturate toe chamber. In order to insure beta sensitivity, the front window has an equivalent thickness of approximately 7 mg/cm/sup 2/. The measuring device is a line-operated electrometer circuit equipped with an alarm that may be set at the rejection limit for the type of garment being monitored. A fullscale deflection on the most sensitive range is given by 2 to 3 mu C of liquid mixed fission products deposited on a garment. Since the chamber monitors the entire garment, the results are independent of the location of the contarnination. In practice, garments may be monitored at the rate of 7 per min, while only 3 per min may be completely checked with a GM tube probs. Field tests indicate that this instrument is stable and trouble free. Background causes a meter deflection of about 20 divisions, which is low enough to give reliable accuracy for monitoring garments. (auth)

• Research Organization: Brookhaven National Lab., Upton, N.Y.
• NSA Number: NSA-13-007675
• OSTI ID: 4275908
• Report Number(s): BNL-531
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-59
• Country of Publication: United States
• Language: English

Related Subjects

INSTRUMENTS
BACKGROUND
BETA DETECTION
CIRCUITS
CLEANING
CLOTHING
CONFIGURATION
CONTAMINATION
DISTRIBUTION
EFFICIENCY
ELECTRIC POTENTIAL
ELECTRODES
ELECTROMETERS
ERRORS
FISSION PRODUCTS
HOT WORKING
IONIZATION CHAMBERS
LIQUIDS
MIXING
MONITORING
OPERATION
PLANNING
QUANTITATIVE ANALYSIS
RADIATION DOSES
SENSITIVITY
STABILITY
TESTING
THICKNESS
VOLUME
WINDOWS