General Information

Serial #

96580

Part Number

1

Total Parts

1

AKA

N/A

Patents

N/A

General Description

Bakelite case and adjustment screws. Glass window. Metal scale.

Dimensions

Note: These reflect the general size for storage and are not necessarily representative of the object's true dimensions.

Length

8.9 cm

Width

7.0 cm

Height

N/A

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Communications

Category

Service-test equipment

Sub-Category

N/A

Manufacturer

AKA

Ferranti

Country

England

State/Province

Unknown

City

Unknown

Context

Country

Unknown

State/Province

Unknown

Period

Unknown

Canada

Used by the NRC in Applied Physics, Photometry and Optical instruments.

Function

Measures direct current in milliamperes.

Technical

British-made permanent magnet moving coil type DC portable milliammeter. This meter has a zeroing screw for adjusting the at rest position of the pointer. It also has an unusual feature controlled by a second screw. It is probably used to calibrate the torque produced when the current flows through the meter. This is an important development because it makes it much easier to keep the meter accurate and thus reduces the need to send the meter back to the manufacturer. This invention may be described in Great Britain patent 350,380, accepted June 1 1931. However, the patent mentions that it is used for moving iron instruments, not moving coil ones.

Area Notes

Unknown

Details

Markings

On scale: 'MILLIAMPERES/ FERRANTI/ MADE IN ENGLAND/ PATENT NO 350380./ B.S.1 TYPE NO. 36P./ NO. 96580' ; NRC sticker: 'NATIONAL RESEARCH COUNCIL/ APPLIED PHYSICS/ 3064CC/ PHOTOMETRY 7 OPTICAL INSTR.'

Missing

Missing one adjustment screw.

Finish

Black.

Decoration

N/A