General Information

Serial #

12748

Part Number

1

Total Parts

1

AKA

N/A

Patents

N/A

General Description

Bakelite case mounted on wooden frame (NRC modification). Glass window. Metal screws, binding posts, and scale.

Dimensions

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

Length

N/A

Width

6.6 cm

Height

10.8 cm

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

The artifact was used by the National Research Council in their Applied Physics division. It was used in both Photometry and Optical instruments departments.

Function

Measures voltage in volts.

Technical

British-made permanent magnet moving coil type DC panel voltmeter. 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. The fact that this meter is mounted at an angle on the wooden structure shows that its movement is designed to allow for reasonable accuracy even when the instrument is not completely vertical. Used in a laboratory with optical instruments.

Area Notes

Unknown

Details

Markings

On scale: 'FERRANTI/ VOLTS/ MADE IN ENGLAND/ PATENT No. 285633/ AND PENDING 1000 OHMS PER VOLT/ B.S.1/ No. 12748' ; NRC sticker: 'NATIONAL RESEARCH COUNCIL/ APPLIED PHYSICS/ 3064 CC/ PHOTOMETRY & OPTICAL INSTR.'

Missing

N/A

Finish

Black.

Decoration

N/A