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-rang 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 final 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)

Relitive 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