Ludlum Model 375 Area Monitor

Model 375 Area Monitor by LudlumDigital Display

Part# 48-2230

The Model 375 Area Monitor is a compact digital device designed for monitoring radiation areas. This monitor accommodates a wide choice of detectors for varying applications; it is equipped with a local readout and alarms. These monitors may be connected to an optional auxiliary indicators and annunciators in remote locations. The user-friendly, digital design enhances setup and operation. The Model 375 can be networked to a central PC-based station where data and alarms are logged.

Model 375 Specifications

Indicated Use: Area monitoring
Compatible Detectors: G-M, proportional, scintillation, and neutron
Display: 4 digit LED display with 0.8"(2cm) character height
Display Range: 000.0 - 9999
Display Units: Can be made to display in microR/hr, mR/hr, R/hr, microSv/h, mSv/h, Sv/h, microrem/hr, mrem/hr, rem/hr, cpm, cps, and others
Linearity: Reading within plus or minus 10% of true value with detector connected
Response: Typically 3 seconds from 10% to 90% of final reading
Status: (green light) Indicates the instrument is functioning properly
Low Alarm: Indicated by a yellow light and slow beep (1 per second) audible tone (can be set at any point from 0.0 - 9999)
High Alarm: Indicated by a red light and fast beep (4 per second) audible tone (can be set at any point from 0.0 - 9999)
Note:Audible indicators can be configured as a single beep if desired.
Det Fail: (red light and audible tone; greater than 68 Db at 2 feet) Indicates detector overload, no count from detector, or instrument failure
Low Bat: (yellow) Indicates less than 2 hours of battery power remaining
Connector: Series "C" (others available )
Calibration Controls: Accessible from front of instrument (protective cover provided )
High Voltage: Adjustable from 200 - 2500 volts
Threshold: Adjustable from 2 - 100 mV
Dead Time: Adjustable to compensate for dead time of the detector and electronics (can be read on the display)
OverLoad: Senses detector saturation (indicated by display reading"-OL-")
Over Range: Indicates the radiation field being measured has exceeded the
counting range of the instrument (indicated by display reading "----")
Data Output: 9 pin connector providing 5 decade log output, RS-232 output, signal ground connection, FAIL and Alarm signals (current sink), and direct connection to battery and ground
Remote(optional): Model 271, or Model 272 remote units
Power: 95 - 135 VAC (178 - 240 VAC available), 50 - 60 Hz single phase (less than 100 mA), 6 volt sealed lead acid rechargeable battery (built in)
Battery Life: Typically 48 hours in non-alarm condition, 12 hours in alarm condition
Battery Charger: Battery is continuously trickle charged when instrument is
connected to line power and turned on
Construction: Aluminum housing with ivory polyurethane enamel paint
Temperature Range: -4 degrees F(-20 degrees C) to 122 degrees F(50 degrees C)
May be certified for operation from -40 degrees F(-40 degrees C) to 150 degrees F(65 degrees C)
Size: 7.4" (18.7 cm)H X 9.7" (24.6 cm)W X 2.5" (6.4 cm)L
Weight: 6.5 lbs (2.3 kg)

Commonly Used Detectors
MODEL 133 SERIES - G-M Detectors
MODEL 44-2 - Gamma Scintillator
MODEL 42-30 - Neutron Detector

Optional Accessories

Remote Displays
Time Date Stamp

For Gamma Monitoring

For Neutron Monitoring

Model 133 Series
Model 44-2
Model 44-3
Model 44-6
Model 44-10
Model 44-38
Model 44-62

Model 42-30

Model 375 Area Monitor Manual


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