Environmental Restoration Group

Ludlum Model 239-1F
Ludlum Product Description
The Model 239-1F Floor Monitor is a gas proportional floor monitor detector mounted on a roll-around cart. The instrument features a flow system, quick-connects, a gas bottle mount, and a means to adjust the height of the detector from the floor for optimum performance. A nuclear counting gas bottle, gas regulator, and a survey instrument are required for the operation of the floor monitor. This unit is supplied with the Model 12 Analog Ratemeter. Specify detector upon ordering.

Specifications

INDICATED USE: Floor Monitoring for Alpha, Beta Gamma
DETECTOR: Gas proportional
RECOMMENDED COUNTING GAS: P-10 (10% methane; 90% argon)
BOTTLE SIZE: Typically used with Matheson size 2 or Linde Q
WINDOW: 0.8 mg/cm2 aluminized mylar (window thicknesses of 0.4, 3.9, or 7.9 mg/cm2 are available)
ACTIVE AREA: 584 cm2
OPEN AREA: 425 cm2
EFFICIENCY (4pi): 17%-239Pu; 25%-90Sr/90Y; gamma - less than 1%
GAS RECHARGE: Will operate on static charge for 2 hours
SUGGESTED INSTRUMENTS: Typically used with Model 12, 2221, 2224-1, 2350-1 or 2360
DETECTOR HEIGHT: Adjustable from 0.125"- 3" (0.32 - 7.6 cm) from surface
DETECTOR OPERATING VOLTAGE:
Alpha: Typically 1000 - 1200 volts
Beta Gamma: Typically 1600 - 1800 volts
THRESHOLD: Typically 2 - 4 mV
FLOW METER:
IN - Adjustable from 0 - 100 cc/min
OUT - Flow indicator from 0 - 100 cc/min
GAS CONNECTORS: Double end quick disconnect for 0.25"(0.6 cm) OD tubing
GAS CONSUMPTION: Typically 50 cc/min
CONSTRUCTION:
DETECTOR: Anodized aluminum housing with stainless steel hex protective screen (79%open)
CART: 1" square tubular steel and aluminum with beige powder coat paint, 7.5" (19.1 cm) diameter rear wheels, and 4" (10.2 cm) diameter swivel casters
DETECTOR SIZE: 0.8" H x 6.3" W x 18.3" L (2 x 16 x 46.5 cm)
CART ASSEMBLY: 42" H x 16" W x 27.5" L (106.7 x 40.6 x 69.9 cm) (excluding detector)
WEIGHT: 25 lbs (11.4 kg), excluding gas bottle and counting instrument
8809 Washington St. NE Suite 150
Albuquerque, NM 87113
Tel: (505) 298-4224
Fax: (505) 797-1404