Triangle calculator
The triangle calculator or Knemeyer is an instrument for calculating the wind triangle .
Structure and functionality
It is a calculating disc rule with two sides that enables triangular calculations according to the sine law .
history
It was invented by Siegfried Knemeyer in 1936 and was used as a navigation aid by the air forces of the German Wehrmacht until the end of the Second World War .
The first DR 2 model was produced by Dennert & Pape from 1937 .
Variations
The triangle calculator was manufactured in 3 known models. These were named DR 2 , DR 3 and DR 4 .
Nothing is known about the existence of a DR 1 model , but there are suspicions that it was a prototype.
As far as is known, the DR 2 model was produced from June 1936 to November 1942 and is 153 mm wide and 13 mm high.
DR 3 was riveted, not screwed, and was made in two versions with fluorescent and non-fluorescent material. The oldest known example was produced in March 1943.
The DR 4 version was introduced in November 1944. It was the first new model with a significant change in operation and functionality. With the introduction of another slide rule, it was possible to calculate the drift as well as the wind triangle.
See also
Individual evidence
- ↑ Luftwaffe DR 2 Navigation Computer in WW2 Luftwaffe Personal Equipment. Retrieved June 24, 2017 .
- ↑ The triangle calculator. (No longer available online.) Erwin Wiedmer, formerly in the original ; Retrieved May 5, 2017 . ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ a b c d e Ronald van Riet: Knemeyer triangle calculator. Andrew Mitchell, accessed May 5, 2017 .
- ↑ Hans Dennert: DENNERT & PAPE and ARISTO Slide Rules 1872 - 1978 . tape 6 , no. 1 , March 1997, p. 5 .
- ↑ triangle computer model DR 2, Fl 23,825th In: Imperial War Museum. Imperial War Museums, accessed May 5, 2017 .
