Ludlum Model 2221

• RATEMETER: Provides a four-decade analog display that is operational any time the instrument is turned on, the ratemeter can also be presented on the accompanying LCD as a digital value when the LCD is switched to the “Dig Rate” position
• SCALER: Range from 0-999999 counts
• TIMER: Switch selectable divisions of 0.1, 0.5, 1, 2, 5, 10 minutes or CONT (continuous) for manual timing
• CONCURRENT USE Scaler or digital ratemeter is active when not selected, allowing for concurrent use
• SUGGESTED DETECTORS: GM, proportional, scintillation
• HIGH VOLTAGE: Adjustable from 400-2400 volts (can be checked on display)
• THRESHOLD: Adjustable from 100-1000 (can be checked on display)
• WINDOW: Adjustable from 0-1000 above threshold setting (can be turned on or off)
• GAIN: Adjustable from 1.5-100 mV at a threshold setting of 100
• OVERLOAD: Sense detector saturation, indicated by “—-” on LCD display and meter going to full scale (adjustable depending on detector selected)
• CONNECTOR: Series “C” type
• METER DIAL: 0-500 cpm, 50-500k cpm logarith mic scale (others available)
• DIGITAL DISPLAY: 6-digit LCD display with 1.3 cm (0.5 in.) high digits
• LCD BACKLIGHT: Activated by LAMP switch
• AUDIO: Built-in unimorph speaker with volume control
• AUDIO DIVIDE: Toggle switch for 1, 10, or 100 events per click
• AUDIO JACK: For operational headset
• CONTROLS:
  • Power Switch: On/off
  • Scale Selector Switch: x1, x10, x100, x1K, Log
  • Meter Zero Pushbutton: To zero meter
  • Audio Volume Knob: Adjusts volume of audio output
  • Audio Divide Switch: Divides audio clicks by either 1, 10, or 100
  • Meter Lamp Switch: Illuminates meter
  • Response Switch: Toggles between FAST (4 sec.) or SLOW (22 sec.) from 10% to 90% of final reading
  • Window Switch: Selects wide open window counts or a narrower setting for viewing a specific energy band
  • Scaler Count Time Selector Switch: 0.1, 0.2. 0.5, 1, 2, 5, or 10 minutes
  • Count Pushbutton: Starts or resets scaler count
  • Count Hold Pushbutton: Stops scaler count and leaves result in the display
  • Scaler/Digital Rate Switch: Selects which mode is presented on the LCD
  • Test Buttons: Battery, high voltage, threshold, wnidow
  • Calibration Controls: Recessed screwdriver adjustments with calibration cover
• POWER: 4 each “D” cell batteries
• BATTERY LIFE: Typically 250 hours with alkaline batteries (battery condition can be checked on digital display)
• SIZE: 22.9 x 10.9 x 25.4 cm (9 x 4.3 x 10 in.) (H x W x L) including handle
• WEIGHT: 2.5 kg (5.5 lb.) including batteries
• RS-232 OUTPUT: This option facilitates exporting data to be read as output to a computer or serial printer from either the ratemeter or scaler reading. SMA connector, PN 4261-148, 9-Pin D-Sub connector, PN 4261-184

Model 44-10 Gamma Detector

• INDICATED USE: Low-Level, wide-energy gamma detection
• SUGGESTED INSTRUMENTS: General purpose survey meters, ratemeters, and scalers
• DETECTOR TYPE: NaI(Tl) scintillator, 5.1 cm (2 in.) dia. x 5.1 cm (2 in.) thick
• EFFICIENCY: ¹²⁵I: 4% | ⁵⁷Co: 20% | ¹³⁷Cs: 9% | ⁶⁰Co: 15%
•  SENSITVITY: Typically 900 cpm per μR/hr (¹³⁷Cs gamma)
• RECOMMENDED ENERGY RANGE: 30 keV – 3.0 MeV
• ENERGY RESPONSE: Energy dependent
• BACKGROUND: 9750 cpm  (10 µR/hr field)
• PHTOMULTIPLIER TUBE: 5.1 cm (2 in.) diameter, magnetically shielded
• OPERATING VOLTAGE: 500 to 1200 volts
• TEMPERATURE RANGE: -20 to 50 °C (-4 to 122 °F), may be certified to operate from -40 to 65 °C (-40 to 150 °F)
• ENVIRONMENTAL RATING: IP65
• CONNECTOR: Series “C”
• CONSTRUCTION: Aluminum with beige powder coat
• SIZE: 6.6 x 27.9 cm (2.6 x 11 in.)
• WEIGHT: 1.04 kg (2.3 lb.)