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Wndsn Quadrant Telemeters

Wndsn Graphical Telemetry Computers: Low tech, high utility distance and altitude nomographs from the Wndsn applied science lab

Wndsn Quadrant Telemeter Tutorials

Making the most out of our graphical telemetry computers.

Like with many complex instruments, there are multiple ways to solve certain problems and to measure the required inputs. Combining the various functions leads to a multitude of advanced uses. See also the printed manual.

Powers of 10 and Scale Jumps

Level: Basic

For measurements that are off the scales or to make use of the finer ranges of the logarithmic center scale, it is sometimes necessary to shift decimal points or 'jump' the scales for more precise measurements.

As input we have:

  • 0.3° measured angular size
  • 18m known object size

If the input is off the scale: shift power of 10

18m isn’t part of the scale, so we have to use 1.8m (18/10) to read the result:

  • Connect 0.3° and 1.8m (18/10) to get 250-400m on the center scale.
    • In scientific notation, 0.3 = 0.3×100
    • 18 = 18×100 becomes 1.8 = 18×10-1
  • Hence, we have to add one zero to the result
    • = 2500-4000m

If the input is too low or high on a scale: shift power of 10

0.3° is too low to read since the string is almost parallel to the scale, so we use 3° (0.3×10):

  • Connect 3° (0.3×10) and 1.8m (18/10) to get 35m on the center scale.
    • In scientific notation, 3 = 0.3×101
    • 1.8 = 18×10-1
  • Hence, we have to add two zeros to the result
    • = 3500m

If powers of 10 are impractical: divide or multiply by an arbitrary factor to jump scales

Should the input numbers be impractical to shift by powers of 10, it’s possible to multiply or divide a scale value by an arbitrary factor that shifts the values on that scale.

We take the 1.8 and multiply it by 2 to move down and further to the center of the scale:

  • Connect 3° (0.3×10) and 3.6m (18/10×2) to get 70m on the center scale.
    • 18 = 18×100 becomes 1.8 = 18×10-1 becomes 1.8×2 = 3.6 = 36×10-1
    • 0.3 = 0.3×100 becomes 3 = 0.3×101
  • Hence, we have to add two zeros to the result and divide by 2
    • = 3500m

If powers of 10 are impractical: divide or multiply by an equal factor on both sides

Should the input numbers be impractical to shift by powers of 10, it’s possible to multiply or divide the values by equal factors on both scales.

Now we also take the 3 and multiply it by 2 to move up and further to the center of the scale:

  • Connect 6° (0.3×10×2) and 3.6m (18/10×2) to get 35m on the center scale.
    • 0.3 = 0.3×100 becomes 3 = 0.3×101 becomes 3×2 = 6 = 0.6×101
    • 18 = 18×100 becomes 1.8 = 18×10-1 becomes 1.8×2 = 3.6 = 36×10-1
  • Equal factors on both sides can be ignored but we still add two zeros to the result
    • = 3500m

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