MODEL 2224-1
Technical Manual
Section 3
Ludlum Measurements, Inc.
Page 3-1
January 2012
Specifications
0
Ranges
: four linear range multiples of ×1, ×10, ×100 and ×1000; used in
combination with the 0-500
CPM
meter dial, providing an overall range of
0-500 kcpm
Thresholds
: beta threshold (
BT
) is adjustable from -2 to -10 millivolts
(mV); alpha threshold (
AT
) is adjustable from -50 to -150 mV
Window (beta only)
: Beta window (
BW
) is adjustable from 20-40 mV
Audio
: dual or single-tone click-per-event (beta only) through a built-in
speaker with an adjustable volume control located on front panel; headset
jack located on the instrument
˝
can
˝
High Voltage
: externally adjustable from 400 to 2000 Vdc
Linearity
: within 10% of true value for the analog rate meter; within 2%
for the LCD
Crosstalk
: no more than 10% of gross alpha counts in beta channel; no
more than 1% of gross beta counts in alpha channel
Response Time
: ×1 range multiplier = 10 seconds, ×10 = 7 seconds,
×100 = 2 seconds, ×1000 = 1.5 seconds; all response times measured
from 10-90% of full scale
Meter
: rugged 1 milliamp (mA), with pivot-and-jewel suspension, 8.3 cm
scale, 250 degree
LCD
: six-digit direct-driven with 6.4 mm characters, a counter overflow
arrow and colons for indicating a count in process
Connector
: Standard series
˝
C,
˝
others available
Section
3