▼ Menu

    
Extras ▼

The 90AV is a vacuum photocell with a 4 sq cm Caesium Antimony cathode. The sensitivity is 45 μA/lm at 100 Volts across the cell. The maximum anode voltage is 100 Volts and the maximum current is 5.0 μA. The dark current is quoted as 0.05 μA at 100 Volts on the anode.

The cathode is based on caesium and antimony that are both too reactive to coat the glass when in air. The small cap in the foreground holds the cathode material that is evaporated onto the glass via an induction heater during manufacture.

Thanks to Gary Follett for supplying the details of the cathode deposition process.

The thin glass tube envelope is 18 mm in diameter, and excluding the B7G base pins is 46 mm tall.

References: Data-sheet, ³⁰⁰² & ¹⁰⁴⁰. Type 90AV was first introduced in 1949. See also 1949 adverts.

Pin Connections

Absolute Maximum Operating Conditions^¶

Thanks to Frank Philipse for supplying the above PDF datasheet.