Alternatives & variations Download PDF datasheet

7904

Bayard-Alpert inverted-geometry ionization-gauge triode designed for high-vacuum pressure measurement in scientific and industrial vacuum systems.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: -
Base pins: -
Nominal heater: 4 V / 1.5 A

Description

Bayard-Alpert inverted-geometry ionization gauge triode for high-vacuum pressure measurement.

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: 4 V
Nominal heater current: 1.5 A
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

Gauge

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Westinghouse 7904 Bayard-Alpert ionization gauge: grid voltage up to +500 V relative to filament; ion collector voltage maximum -100 V. These are gauge electrode ratings, not conventional triode plate voltage. Three tungsten filaments may be selected or configured for gauge operation.

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

1947 Westinghouse

Published operating points and test conditions from this source.

SECTION 1

Gauge

Other

HeaterVoltageNominal
4 V
Nominal
HeaterCurrentNominal
1.5 A
Nominal
MaximumPlateOrOperatingVoltage
500 V
IonCollectorVoltageMaximumMagnitude
100 V
TypicalGridVoltage
150 V
GridVoltageMaximum
500 V