Measuring Distance
Instrument: Wndsn NATO-MIL Telemeter
We calculate the distance to an object of known size by converting the angular size of the object into the absolute value.
Figure 1. Telemeter operation: The measured object is approximately 94 MIL high; the known height of the object is 4 m; we read a distance of approx. 43 m on the D scale.
First, we determine the angular size of the object using the MIL scale of the Telemeter and then use the nomogram to calculate the absolute distance (in the unit of our choice).
Example
- We keep the string tight at a distance of 50 cm (19.7 inches) from eye to scale.
- Then we align the zero line of the instrument with the bottom edge of the object to be measured.
- Then we read the angular size on the MIL scale at the top edge of the object.
- Then we take the instrument down and align the string with the determined value on the MIL scale.
- Then we align the free end of the string with the known height on the S scale.
- Finally, we read the distance on the D scale where the string crosses the scale.
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