General Information

Serial #

29433

Part Number

1

Total Parts

1

AKA

N/A

Patents

N/A

General Description

Bakelite case. Glass window. Paper scale. Leather strip.

Dimensions

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

Length

N/A

Width

5.4 cm

Height

5.1 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Communications

Category

Radio

Sub-Category

N/A

Manufacturer

AKA

Sangamo

Country

England

State/Province

Unknown

City

Enfield

Context

Country

Worldwide

State/Province

Unknown

Period

1941-1950

Canada

Used as part of military communications during WWII. The artifact was made by the English subsidiary of the American company Weston Electrical Instruments Corp.

Function

As part of a radio transmitter, it was used to measure the amount of radio frequency energy being coupled between the transmitter and an antenna. Measures AC current in amperes.

Technical

Good example of small continuously running thermocouple type meter. Weston made many meters specifically for radio frequencies. Thermocouple type meters have the advantage of being able to accurately measure current with very high frequencies because they work by measuring the voltage produced by a thermocouple attached to a heating element. The warming of the element depends only on the amount of current that passes through it, no matter which wave form it has. However, this type of meter cannot accurately measure currents with lower frequencies. (ref. 2) "In 1936 British Sangamo acquired the "Weston Electrical Instrument Co. " of Surbiton, Surrey. This company was the United Kingdom subsidiary of the "Weston Electrical Instrument Corporation", of Newark, New Jersey, USA, a company founded by Dr. Weston (a pioneer in the field of electrical measurements), and recognized as one of the worlds leading manufacturers of electrical measuring and associated equipment. The two companies were combined to form "Sangamo Weston ", which designed and manufactured a wide range of electrical measuring and control equipment. Sangamo Weston became associated with products for the aviation industry and as a result, devoted its entire resources during the 1939-45 war, to the production of measuring instruments, indicators and associated ancillary equipment for use on aircraft. After World War 2 resources were put back into the original product lines but they continued to design and manufacture aircraft measuring instruments, indicators, measuring systems and associated equipment for customers all over the world." (See ref. 1)

Area Notes

Unknown

Details

Markings

Meter scale calibrated 0 to 3 amperes with type of meter etc. below scale. Printed on face: 'AMPERES/ FOR RADIO FREQUENCIES ONLY/ THERMO-COUPLE A [CROWN] M 10A/8480/ WESTON/ 1940 NO./ RES..08 MU'. Stamped on back: 'SER. NO./ 29433'. Embossed in back: 'SANGAMO WESTON LTD./ ENFIELD MIDDX. ENG.'

Missing

N/A

Finish

Black bakelite case. White cardstock scale with black lettering.

Decoration

N/A