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Ludlum Model 19 MicroR/Ratemeter Ludlum Get Quote



The Model 19 is a highly sensitive gamma R/meter employing an internally housed, 2.5 cm diameter by 2.5 cm  thick (1.0 x 1.0 in.) NaI detector. The measuring range is 0-50 v/h  (0-5000 R/hr).  The cast aluminum instrument housing with its separate battery compartment and accompanying metal handle offer an industrial robustness and quality that promote long lasting protection and instrument life.

The front-panel controls include a rotary switch for selecting the five-decade range and instrument shut-off, an audio on/off switch, a fast/slow response switch, and pushbuttons for activating the meter lamp, high-voltage display, battery test, and count reset. 

  • Rotary knob selector: 0-25, 0-50, 0-250, 0-500, 0-5000 r/hr,  instrument off
  • Response: toggle switch for fast (4 seconds) or slow (22 seconds) from 10% to 90% of final reading
  • Audio: built-in unimorph speaker with on/off switch (greater than 60 db at 0.6 meters [2 ft])
  • High voltage: pushbutton to display hv setting on meter
  • Battery: pushbutton checks battery voltage
  • Reset: pushbutton to zero meter
  • Lamp: pushbutton to activate meter light
  • Calibration controls: accessible from front of instrument (protective cover provided)


Technical Specifications

INDICATED USE: low-level (R) gamma survey
MEASUREMENT RANGE: 0-50 Sv/h (0-5000 R/hr)
DETECTOR: 2.5 x 2.5 cm (1 x 1 in.) NaI (Tl) scintillator
SENSITIVITY: 17,500 cpm/Sv/h (175 cpm/R/hr) (137Cs gamma)
ENERGY RESPONSE: energy dependent
LINEARITY: reading of true value
METER: 6.4 cm (2.5 in.) arc, 1 mA analog type
METER DIAL: 0-25 R/hr, 0-50 R/hr, BAT TEST, High Voltage Test
WORKING ENVIRONMENT: splashproof shields for outdoor use
TEMPERATURE RANGE: -20 to 50 °C (-4 to 122 °F), may be certified for operation from -40 to 65 °C (-40 to 150 °F)
POWER: 2 each cell batteries (housed in sealed compartment that is externally accessible)
BATTERY LIFE: typically 2000 hours with alkaline batteries (battery condition can be checked on meter)
CONSTRUCTION: cast and drawn aluminum with beige polyurethane enamel paint
SIZE: 15.2 x 8.9 x 21.6 cm (6.0 x 3.5 x 8.5 in.) (H x W x L), without handle
WEIGHT: 2.04 kg (4.5 lb), including batteries