Tachometer, Air Ministry, Mk IA, 6C/223 (Serial 134/42)
This artifact resides in our Private Collection, yet we welcome inquiries from restorers, museums, or serious enthusiasts. Please email us with the name of the artifact at Curator@AeroAntique.com.
Here is a WWII-era Mk IA chronometric (mechanical) tachometer of the British Royal Air Force, Air Ministry stores reference number 6C/223, serial number 134/42. This tachometer measures from 500 to 5000 RPM, and has a totalizing counter which measures up to the millions of RPM. The "6C" prefix in the stores reference number indicates that this tachometer was intended as a test instrument, and the "42" in the serial number indicates a manufacturing year of 1942.
A flexible cable shaft would be affixed to the connector at the bottom for measurement. The indicator is in good condition given its age. The yellow pointer is a bit loose at the center axis and may fall off in shipment, but it could be cemented in place. Measures ~5.5 inches diameter and ~3.5 inches deep.