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  • Ludlum Model 375 Digital Wall-Mount Area Monitor

$1,710.00 $855.00

1 in stock

SKU: 214772029-2 Product Type: , Vendor:

Per the serial number this 375 is a 375/2 which means it uses an internal energy compensated gm tube good from 0.1 mR/hr up to 1000 mR/hr. Typical calibration constant would be 1050 cpm with a typical deadtime setting of about 70-110 µSec.

Based on the last time it was in our service dept. this 375/2 went out the door with a calibration constant setting of 1000 cpm and a deadtime setting of 100 µSec. along with a low alarm of 0.2 mR/hr and a high alarm of 0.4 mR/hr


The Model 375 Digital Wall-Mount Area Monitor is designed for visibility and ease of use.  The unit has variable high voltage and can accommodate energy compensated GM detectors, scintillation detectors, etc.  The range measured is dependent upon the type of detector that is attached.

It features a wall-mount chassis and a four-digit LED display that is readable from 30 feet. Backlit indicators warn of low radiation (yellow), high radiation (red), instrument failure (red), and low battery (yellow), along with an alarm. A green status light is a positive indication of instrument operation.

INDICATED USE: gamma monitoring
DISPLAY: 4-digit LED display with 2 cm (0.8 in.) character height
DISPLAY RANGE: 000.0 to 9999 (Series One: 00.00 to 9999)
OPERATING RANGE: 1 μSv/h to 10 mSv/h (0.1 mR/hr to 1 R/hr)
DISPLAY UNITS: can be made to display in μR/hr, mR/hr, R/hr, μSv/h, mSv/h, Sv/h, μrem/hr, mrem/hr, rem/hr, cpm, cps, and others
LINEARITY: readings within 10% of true value with detector connected
RESPONSE: typically 3 seconds from 10% to 90% of final reading

  • STATUS: (green light) instrument functioning properly
  • LOW ALARM: (yellow light and slow [1 per second] beep) can be set at any point from 0.0 to 9999
  • HIGH ALARM: (red light and fast [4 per second] beep) can be set at any point from 0.0 to 9999
  • DET FAIL: (red light and audible tone) for conditions of detector overload, no count from detector, or instrument failure
  • LOW BAT: (yellow light) indicates less than 2 hours of battery power remaining
  • OVERLOAD: display reading of -OL- and audible FAIL alarm indicate detector saturation
  • OVER-RANGE: display reading of “—-” and activated low and high alarms indicate that the radiation field being measured has exceeded the counting range of the instrument (or when dead time correction accounts for more than 75% of the displayed reading)

REMOTE (optional): allows for connection of Ludlum Model 271 or 272 remote units
CONNECTOR: series “C” (others available)
ETHERNET (optional): 10 Base-T connection for use with Ludlum’s software
CALIBRATION CONTROLS: accessible from the front of instrument (protective cover provided)
HIGH VOLTAGE: user-adjustable from 200 to 2500 volts
DEAD TIME: user-adjustable to compensate for dead time of the detector and electronics (can be read off the display)
AUDIO: can vary from approximately 68 dB to 100 dB through operation of the external rotary baffle and the internal voltage connection
RS-232 OUTPUT: a 2-second dump for computer data logging
POWER: 9 Vdc wall-mount adapter with four sets of prongs for almost any style wall receptacle
BATTERY LIFE: typically 48 hours in non-alarm condition; 12 hours in alarm condition
BATTERY CHARGER: battery is continuously trickle charged when the instrument is connected to line power and turned on
CONSTRUCTION: aluminum housing with ivory powder-coat finish
TEMPERATURE RANGE: -15 to 50 °C (5 to 122 °F); may be certified for operation from -40 to 65 °C (-40 to 150 °F)
SIZE: 18.7 x 24.6 x 6.4 cm (7.4 x 9.7 x 2.5 in.) (H x W x D)
WEIGHT: 2.1 kg (4.7 lb)


For internal use:

Barcode 17256284

Additional information

Weight 7 lbs