Sigma Instrument Co
of Spring Road, Letchworth, Herts. Telephone: Letchworth 446. Telegraphic Address: "Sigma, Letchworth". (1937)
of Letchworth, Herts. Telephone: Letchworth 1045. Cables: "Sigma, Letchworth". (1947)
1937 Listed Exhibitor - British Industries Fair. Gas Calorimeters. Gas and Air Flow Meters. Steam Flow Meters. Pressure Recorders. Automatic Gas Mixing. Relay Operated Exhauster Regulators and Retort House Governors. CO2 Recorders. Distant Recorders and Distant Indicators. (Stand Nos. Ca. 813 and Ca.712) [1]
1947 Listed Exhibitor - British Industries Fair. Manufacturers of Fine Measuring Instruments including Mechanical, Electrical, Optical and Pneumatic Comparators; Automatic Inspection Equipment. Gas Testing Equipment including Recording and Indicating Calorimeters, Specific Gravity and Pressure Recorders, etc. Automatic Control Equipment. (Olympia, Ground Floor, Stand No. A.1074) [2]
1949 Manual or automatic controls for gas production[3]
1969 Two Herbert Group companies, Herbert-BSA Electrics Ltd. and the Sigma Instrument Company Ltd, have been amalgamated to form Herbert Controls ...[4]
1969 Part of Herbert Controls and Instruments.[5]
See Also
Sources of Information
- ↑ 1937 British Industries Fair p413
- ↑ 1947 British Industries Fair p250
- ↑ [1] Historic England
- ↑ Coventry Evening Telegraph 06 November 1969
- ↑ Evening News (London) - Thursday 27 November 1969