120C

Gas-filled Geiger-Müller radiation counter designed for beta and X-ray detection, using a thin mica window and self-quenching fill for stable pulse counting in laboratory radiation instruments.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized

Sections: 1
Base: -
Socket code: -
Base pins: -
Nominal heater: -

Description

120C is a Other device. Permanent-sensitivity gas-filled radiation counter tube for Beta & X-Ray detection. Published operating, rating, and characteristic data from the supplied page were preserved in the technical output.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: -
Base pins: -
Nominal heater voltage: -
Nominal heater current: -
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

1 physical section, each with unique specifications.

Section 1

GeigerMullerCounter

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Permanent-sensitivity gas-filled radiation counter tube for Beta & X-Ray detection.

Source-dependent data

Operating conditions by source

Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.

Data set 01

1958 Amperex Industrial

Published operating points and test conditions from this source.

SECTION 1

GeigerMullerCounter

Other

Filling
Argon + quenching admixture
Operating voltage
1200 V
DC
Window thickness
0.0008 in
MicaWindow
Window areal density
5.6 mg/cm2
MicaWindow
Effective mica-window diameter
1-29/32 in
Cathode dimensions
2-11/16 long x 2 OD x 5/64 wall
Maximum overall tube dimensions
2-3/8 x 5-1/8
Radiation application
Beta & X-Ray
Operating temperature range minimum
-55 degC
Operating temperature range maximum
75 degC

Characteristic

Plateau length
in excess of 300 V
Plateau slope
5% to 10% per 100 V
Dead time
300 us
Approximate
Maximum shielded background
100 counts/min
Shielded by 2 inches of lead