Vintage Casella Low Speed Air Speed Meter / Anemometer T16320

This wonderful looking 1940s anemometer is a 7cm / 2¾ inch Vintage Casella Low Speed Air Speed Meter / Anemometer T16320 in its original velvet lined leather travel case.

This is a small type of anemometer/ air speed meter with flat vanes which indicate the number of linear feet of air passing through the instrument during its exposure. A small portable device generally used to measure air flow in ducting, fan openings etc, in a range of environments where the air speed doesn't exceed the maximum stated velocity. 

• Air Meter Serial number 5516
• Type: T.16320
• Dial range 1000 metres
• Speed Range 15-350 metres/min
• Correction:  8 metres/min addition to the observed reading

The instrument is in good working condition, with some surface blemishes on the dial, but I can't attest to its accuracy. It comes in its original maroon velvet lined leather case, which is worn and discoloured with blemishes, a correction card, and a leaflet with general information on the use of an air meter.

It has 8 Mica (silicated mineral) vanes and 2 dials measuring 0-90 on the outer dial and 0-9 on the smaller inner dial. It has an on/off lever and a zero reset button. 

Approximate Size:

• Diameter of Anemometer 7 cm / 2¾ "
• Dial Diameter: 5.5cm
• Leather Transit Case
  • Width: 10 cm
  • Depth: 8.4 cm
  • Height: 9 cm

Manufactured by CF Casella & Co, London (established in 1799 and suppliers of scientific equipment to eminent scientists and engineers, including Charles Darwin).

Mechanical anemometers were a piece of safety equipment, invented by Benjamin Biram in 1844, to determine the volume of air entering or exiting mine workings. They were produced in 2 styles; Biram style which have the dials and vanes on the same plane and the offset style which has the dials perpendicular to the vanes. 

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