General Purpose Ratemeter
Features
• Low Price
• Rugged
• 5-Decade Analog Ratemeter
• Operates Two Detectors
- Built-in Internal GM Detector
- External GM or Scintillator Detector
Introduction
The general purpose, handheld analog ratemeter supports operating two separate radiation detectors.
This instrument is set for 900-volt GM tube operation and is typically used with an external, thin-wall GM tube
or pancake GM. Other external detectors are compatible. An internal energy-compensated, high-range
detector is used for the x10000 range only. This detector is active whenever the instrument is on and in a
very high radiation feld, and it will drive the meter needle to full scale, thus alerting the user.
A switch allows the operator to select between the internally mounted GM detector with an exposure
range of 0 to 20 mSv/h (0 to 2000 mR/hr) or an external GM or scintillator detector of choice
Specifcations
APPLICATION: alpha, beta, gamma survey
COMPATIBLE DETECTORS: GM, scintillation
DETECTOR CHANNELS : x0.1 through x100 range settings read out the external detector channel, x1000 reads out the internal GM detector
EXTERNAL DETECTOR: any GM or scintillator operating on 900 Vdc
INTERNAL DETECTOR : energy compensated GM, 0–20 mSv/h (0–2000 mR/hr), used with x1000 scale only
ENERGY RESPONSE: within 15% of true value between 60 keV–3 MeV (internal detector only)
LINEARITY: reading within 10% of true value with detector connected
HIGH VOLTAGE: 900 volts
THRESHOLD: -40 mV ±10 mV
CONNECTOR : series “C”
METER : 6.4 cm (2.5 in.) arc, 1 mA analog type
METER DIAL: typically 0–2 mR/hr and cpm, BAT TEST (others available)
CONTROLS:
Rotary Selector Switch: switches instrument to Off or ranges: x0.1, x1, x10, x100 x1000
Response Switch: toggles between FAST (4 seconds) or SLOW (22 seconds) from 10% to 90% of fnal reading
Reset Pushbutton: to zero meter
Battery Pushbutton: checks battery status
Audio Switch: audio on/off, built-in unimorph speaker, greater than 60 dB at 0.6 meters (2 ft)
POWER: 2 each “D” cell batteries (housed in an externally accessible sealed compartment)
BATTERY LIFE : typically greater than 2000 hrs (battery condition can be checked on meter); LOW BAT warning
CONSTRUCTION: cast and drawn aluminum with beige powder coating
TEMPERATURE RANGE : -20 to 50 °C (-4 to 122 °F)
RELATIVE HUMIDITY: < 95%
SIZE: 16.5 x 8.9 x 21.6 cm (6.5 x 3.5 x 8.5 in.) (H x W x D)
WEIGHT : 1.6 kg (3.5 lb), including batteries
