Model 2241 Survey Meter

General Purpose Survey

Ludlum 2241 digital radiation survey meter

For Alpha, Beta and Gamma Radiation

The Model 2241 is variation of the Model 3. Added features are the digital readout and scaler function. The survey meter is used for general survey and gross counting with GM, proportional or scintillation detectors. Display range is auto ranging from 0.0 mR - 9999 mR, 0.000 mSv/h -9990 mSv/h; 0 cpm - 999k cpm; or 0 cps - 100 cps. The 2241 meter is supplied as shown with built-in speaker, strain relief cable, probe clip on handle, two D batteries, and standard factory calibration. The 2241-2 meter includes a control for 2 HV settings. The 2241-3 meter includes a control for using three different probes.

Newer Models are now available, with larger display and multiple units.

INDICATED USE: General purpose survey, gross counting
COMPATIBLE DETECTORS: G-M, proportional, scintillation
CONNECTOR: Series "C" (others available on request)
AUDIO: Built in unimorph speaker with ON/OFF switch (greater than 60 dB at 2 feet)
ALERT/ALARM: Indicated by enunciator on display and audible tone
DISPLAY: 4 digit LCD display with 0.5"(1.3cm) high digits, separate enunciators for display units, alert, alarm, low battery, detector overload, counting overflow, and scaler counting
BACKLIGHT: Push-button to activate
RATEMETER: Can display in R/hr, Sv/hr, cpm, or cps when control switch is in RATEMETER position
DISPLAY RANGE: Auto ranging from 0.0 microR/hr - 9999 R/hr; 0.000 microSv/hr - 9999 Sv/hr; 0 cpm - 999k cpm; or 0 cps - 100k cps
LINEARITY: Reading within plus or minus 10% of true value with detector connected
SCALER: Activated by push-button in handle (count time adjustable from 1 - 9999 seconds in 1 second intervals)
CALIBRATION CONTROLS: Accessible from front of instrument (protective cover provided)
HIGH VOLTAGE: Adjustable from 200 - 2500 volts
DISCRIMINATOR: Adjustable from 2 - 100 mV
OVERLOAD: Indicated by OVERLOAD on display (adjustable depending on detector selected)
RESET: Push-button to zero display, acknowledge and/or reset alarm
POWER: 2 each "D" cell batteries (housed in sealed compartment that is externally accessible)
BATTERY LIFE: Typically 200 hours with alkaline batteries (24 hours when low battery is first indicated on display)
CONSTRUCTION: Cast and drawn aluminum with beige polyurethane enamel paint
TEMPERATURE RANGE: -4° F(-20° C) to 122° F(50° C)
May be certified for operation from -40° F(-40° C) to 150° F(65° C)
SIZE: 6.5"(16.5cm)H X 3.5"(8.9cm)W X 8.5"(21.6cm)L
WEIGHT: 3.5 lbs (1.6kg) including batteries

The following parameters are adjusted by removable switchboard. Once initial setup and calibration have been completed the switchboard can be removed without affecting normal operation of the instrument (Model 2241 may be ordered without switchboard)

BACKLIGHT "ON" TIME: 5, 30, 60, 90, 180, or 240 seconds for the backlight to stay "ON" when activated.
SET MINIMUM DISPLAY: Allows lower limit of auto-ranging display to be fixed. For example, display can be set to not show values less than 1 R/hr.
RS-232 DATA DUMP MODE: Enables or disables dump mode to RS-232 port. When enabled data will be dumped every 2 seconds
RS-232 DETECTOR SETUP MODE: Allows for detector parameters to be input by RS- 232 port
BAUD RATE: 150, 300, 600, 1200, 2400, 4800, 9600, or 19200 bps.
DEAD TIME: Adjustable from 0 - 9999 seconds
CALIBRATION CONSTANT: Adjustable from 0.001 - 280 X 109 counts/display unit
DISPLAY UNITS: Can read in R/hr, Sv/hr, cpm, or cps
TIME BASE: Can read in seconds or minutes
AUDIO DIVIDE: 1, 10, 100, or 1000 events-per-click
RESPONSE:
FIXED: FAST response time adjustable from approximately 2 - 50 seconds. SLOW response is 5 times fast setting
VARIABLE: Dependent on number of counts present. Typical times FAST - 4 - 25 seconds, SLOW - 4-60 seconds
(All times stated from 10% to 90% of final reading)
RATEMETER ALERT/ALARM: Set at any point corresponding to pre-selected ratemeter range
SCALER ALARM: Adjustable from 1 - 999999 counts
SCALER COUNT TIME: Adjustable from 1 - 9999 seconds

Manual