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Ludlum Medical Physics Model 9-4

Ion Chamber Radiation Survey Meter

Features

5 Ranges from Background to 50 R/hr
1000 mg/cm² Retractable Beta Shield
Automatic Temperature & Pressure Compensation
Low Battery Warning
High Background Zero Capability
PC-Controlled Calibration

Introduction

The Ludlum 9-4 is a rugged air ionization chamber for performing beta-gamma radiation dose rate measurements over a 5 decade span ranging from background to 50 R/hr. The ion chamber automatically compensates for changes in temperature and pressure. The chamber wall, including the instrument case, is 1000 mg/cm². A 1000 mg/cm² retractable beta shield allows beta measurement with a 7 mg/cm² window.

The six position selector switch selects Off, x10K, X1K, X100, X10 and X1. Other controls include an on/off switch for a meter light, reset and battery test buttons and a zero adjustment knob.

The Model 9-4 is equipped with a serial interface for calibration. An optional calibration kit is available that supplies the necessary interface cable, software, calibration can, pressure pump and serial-to-USB converter.

Specifications

PART NUMBER: 48-3739

APPLICATION: Gamma and X-ray exposure survey meter with beta response
RANGE: 0 - 50 R/hr

ENERGY RESPONSE: +/- 20% of true value from 40 keV - 2 MeV

LINEARITY: Reading within 10% of true value

RESPONSE TIME: Approximately 5 seconds for 90% of final meter deflection on the x1 and x10 scales, and 3 seconds on the x100, x1k and x10k scales
BETA RESPONSE: Factor of 4.8 difference between window open and closed measurements when exposed to a uranium slab
CHAMBER VOLUME: 220 cm³

CHAMBER CONSTRUCTION: Carbon coated acrylic

SIDE WALL: 1000 mg/cm² aluminum and acrylic

BETA SHIELD: Retractable 1000 mg/cm² phenolic slide with side button control

WINDOW: 7 mg/cm² aluminized mylar

WINDOW AREA: 40 cm²

COMPENSATION: Automatically corrects for temperature and pressure changes in atmosphere

TEMPERATURE RANGE: -4° to 122° F (-20° to 50° C). Temperature compensation maintains calibration within 15% of 25° C reading
PRESSURE COMPENSATION RANGE: 70 kPa to 106 kPa
METER: 2.5” (6.4 cm) arc, 1 mA, pivot-and jewel suspension

METER DIAL: 0 - 5 mR/hr, BAT TEST

CONTROLS:

Range Switch: 5 range multipliers x1, x10, x100, x1k, x10k and instrument off
Reset: Pressing the reset button causes the chamber to discharge
Bat Test: Pushbutton used to check battery capacity
Zero Adjust: 1 turn potentiometer to zero reading
Display Light: On/off switch
Calibration: Digitally set via USB to serial computer interface, stored in non-volatile memory

BATTERY LIFE: 400 hours

POWER: 2 each “D” cell batteries housed in a sealed externally-accessible compartment
CONSTRUCTION: Cast and drawn aluminum with beige powder-coating

SIZE: 9.2” H x 3.5” W x 8.5” L (23.4 x 8.9 x 21.6 cm) including instrument handle

WEIGHT: 4.2 lbs (1.9 kg) including batteries

Meter Face

Technical Information

Alternate Instruments

Model 9-3 - Same as Model 9-4 less pressure compensation with audio output and screw driver adjusted calibration.

Other Ludlum Medical Physics Products

Other Ludlum Medical Physics Products

Ludlum Medical Physics Information

For more information or to request a quotation, please contact us

by phone at: (865) 947-5123 or by email at: sales@deqtech.com.