Chronometric Tachometer / Disk Speed Indicator BS Mk15 for Testing Norden Sight F-100 The fluid is low by

The fluid is low by about a 1/2 teaspoon

While flying at the selected limit

A Yellow (Minus Blue) filter is attached

such as the P-40

The anchor symbol of the US Navy appears on the rear of the instrument

Chronometric Tachometer / Disk Speed Indicator BS Mk15 for Testing Norden Sight F-100 The fluid is low byHere is a WWII era Chronometric Tachometer Disk Speed Indicator Kit, made by Technical Oil Tool Co. (TOTCO), used by bombardiers and technicians to check the proper operation of the Norden Bombsight The kit contains the disk speed indicator, two tachometer tips, instructions, and a metal case with a rubber lined compartment. It is in very good condition given its age. The case measures ~4. 5 inches long, 3 inches wide, and ~1. 5 inches deep.