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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.


Measuring MIL with the Telemeter

Level: Advanced

[This trick works with all Telemeters that are calculated for an eye distance of 57.3 cm (180/π). For other values ​​on the α scale, the knots must be adjusted accordingly.]

With an additional knot on the string at 50 cm (19.69 inches) you can take measurements in MIL. The α (angle) scale thus becomes a MIL scale with a resolution of 2 MIL per scale mark (i.e. 2 MIL at 0.1°, 10 MIL at 0.5°, 20 MIL at 1°, etc.).

The math behind it: a MIL, also known as a milliradian, is the angle at which an object with a size of 1 unit is seen at a distance of 1000 units. This means that an object with a width of one centimeter at a distance of 1000 centimeters has an angular size of one MIL.

The perceived image of this object at a distance of 50 centimeters from the observer then corresponds to:

1 cm / 1000 cm · 50 cm = 50 cm / 1000 cm = 0.05 cm = 0.5 mm

Since the α scale of the Telemeter corresponds to a metric scale with 1 mm distance per 0.1°, one millimeter corresponds to an angle size of 2 MIL. After we have measured the angular size of our object in MIL, we can do the further calculations of the distance or the object size with the MKS formula, as described in our tutorial under MIL vs. MRAD vs. NATO-MIL and use all the advantages of the measurement in MIL.

What if the object is bigger or closer? The answer is to extend the angle scale. How? Using additional knots on the string, as described in Extending the Scales.

In order not to mix up the knots for the measurements in degrees and for the measurements in MIL, it is advisable to mark the new knots with permanent marker or colored string.

In the table below you can find further positions for further knots on the string to expand the scales in MIL, as well as multipliers to calculate the distance more quickly if the size is known. These multipliers can also be used as divisors for calculating the sizes or heights when the distance is known. Of course, the Telemeter nomogram on the MIL calculator can be used with the MIL input. (The Telemeter nomogram in degrees does not work in MIL.)

Scale [mm] String length [cm]
50 25 20 12.5 10
MIL Multiplier Angle MIL Multiplier Angle MIL Multiplier Angle MIL Multiplier Angle MIL Multiplier Angle
0 0 0 0 0 0 0 0 0 0 0
1 2 x500.0 0.11° 4 x250.0 0.23° 5 x200.0 0.29° 8 x125.0 0.46° 10 x100.0 0.57°
2 4 x250.0 0.23° 8 x125.0 0.46° 10 x100.0 0.57° 16 x62.5 0.92° 20 x50.0 1.15°
3 6 x166.7 0.34° 12 x83.3 0.69° 15 x66.7 0.86° 24 x41.7 1.37° 30 x33.3 1.72°
4 8 x125.0 0.46° 16 x62.5 0.92° 20 x50.0 1.15° 32 x31.3 1.83° 40 x25.0 2.29°
5 10 x100.0 0.57° 20 x50.0 1.15° 25 x40.0 1.43° 40 x25.0 2.29° 50 x20.0 2.86°
6 12 x83.3 0.69° 24 x41.7 1.37° 30 x33.3 1.72° 48 x20.8 2.75° 60 x16.7 3.43°
7 14 x71.4 0.80° 28 x35.7 1.60° 35 x28.6 2.00° 56 x17.9 3.21° 70 x14.3 4.00°
8 16 x62.5 0.92° 32 x31.3 1.83° 40 x25.0 2.29° 64 x15.6 3.66° 80 x12.5 4.57°
9 18 x55.6 1.03° 36 x27.8 2.06° 45 x22.2 2.58° 72 x13.9 4.12° 90 x11.1 5.14°
10 20 x50.0 1.15° 40 x25.0 2.29° 50 x20.0 2.86° 80 x12.5 4.57° 100 x10.0 5.71°
11 22 x45.5 1.26° 44 x22.7 2.52° 55 x18.2 3.15° 88 x11.4 5.03° 110 x9.1 6.28°
12 24 x41.7 1.37° 48 x20.8 2.75° 60 x16.7 3.43° 96 x10.4 5.48° 120 x8.3 6.84°
13 26 x38.5 1.49° 52 x19.2 2.98° 65 x15.4 3.72° 104 x9.6 5.94° 130 x7.7 7.41°
14 28 x35.7 1.60° 56 x17.9 3.21° 70 x14.3 4.00° 112 x8.9 6.39° 140 x7.1 7.97°
15 30 x33.3 1.72° 60 x16.7 3.43° 75 x13.3 4.29° 120 x8.3 6.84° 150 x6.7 8.53°
16 32 x31.3 1.83° 64 x15.6 3.66° 80 x12.5 4.57° 128 x7.8 7.29° 160 x6.3 9.09°
17 34 x29.4 1.95° 68 x14.7 3.89° 85 x11.8 4.86° 136 x7.4 7.74° 170 x5.9 9.65°
18 36 x27.8 2.06° 72 x13.9 4.12° 90 x11.1 5.14° 144 x6.9 8.19° 180 x5.6 10.20°
19 38 x26.3 2.18° 76 x13.2 4.35° 95 x10.5 5.43° 152 x6.6 8.64° 190 x5.3 10.76°
20 40 x25.0 2.29° 80 x12.5 4.57° 100 x10.0 5.71° 160 x6.3 9.09° 200 x5.0 11.31°
21 42 x23.8 2.41° 84 x11.9 4.80° 105 x9.5 5.99° 168 x6.0 9.54° 210 x4.8 11.86°
22 44 x22.7 2.52° 88 x11.4 5.03° 110 x9.1 6.28° 176 x5.7 9.98° 220 x4.5 12.41°
23 46 x21.7 2.63° 92 x10.9 5.26° 115 x8.7 6.56° 184 x5.4 10.43° 230 x4.3 12.95°
24 48 x20.8 2.75° 96 x10.4 5.48° 120 x8.3 6.84° 192 x5.2 10.87° 240 x4.2 13.50°
25 50 x20.0 2.86° 100 x10.0 5.71° 125 x8.0 7.13° 200 x5.0 11.31° 250 x4.0 14.04°
26 52 x19.2 2.98° 104 x9.6 5.94° 130 x7.7 7.41° 208 x4.8 11.75° 260 x3.8 14.57°
27 54 x18.5 3.09° 108 x9.3 6.16° 135 x7.4 7.69° 216 x4.6 12.19° 270 x3.7 15.11°
28 56 x17.9 3.21° 112 x8.9 6.39° 140 x7.1 7.97° 224 x4.5 12.63° 280 x3.6 15.64°
29 58 x17.2 3.32° 116 x8.6 6.62° 145 x6.9 8.25° 232 x4.3 13.06° 290 x3.4 16.17°
30 60 x16.7 3.43° 120 x8.3 6.84° 150 x6.7 8.53° 240 x4.2 13.50° 300 x3.3 16.70°
31 62 x16.1 3.55° 124 x8.1 7.07° 155 x6.5 8.81° 248 x4.0 13.93° 310 x3.2 17.22°
32 64 x15.6 3.66° 128 x7.8 7.29° 160 x6.3 9.09° 256 x3.9 14.36° 320 x3.1 17.74°
33 66 x15.2 3.78° 132 x7.6 7.52° 165 x6.1 9.37° 264 x3.8 14.79° 330 x3.0 18.26°
34 68 x14.7 3.89° 136 x7.4 7.74° 170 x5.9 9.65° 272 x3.7 15.22° 340 x2.9 18.78°
35 70 x14.3 4.00° 140 x7.1 7.97° 175 x5.7 9.93° 280 x3.6 15.64° 350 x2.9 19.29°
36 72 x13.9 4.12° 144 x6.9 8.19° 180 x5.6 10.20° 288 x3.5 16.07° 360 x2.8 19.80°
37 74 x13.5 4.23° 148 x6.8 8.42° 185 x5.4 10.48° 296 x3.4 16.49° 370 x2.7 20.30°
38 76 x13.2 4.35° 152 x6.6 8.64° 190 x5.3 10.76° 304 x3.3 16.91° 380 x2.6 20.81°
39 78 x12.8 4.46° 156 x6.4 8.87° 195 x5.1 11.03° 312 x3.2 17.33° 390 x2.6 21.31°
40 80 x12.5 4.57° 160 x6.3 9.09° 200 x5.0 11.31° 320 x3.1 17.74° 400 x2.5 21.80°
41 82 x12.2 4.69° 164 x6.1 9.31° 205 x4.9 11.59° 328 x3.0 18.16° 410 x2.4 22.29°
42 84 x11.9 4.80° 168 x6.0 9.54° 210 x4.8 11.86° 336 x3.0 18.57° 420 x2.4 22.78°
43 86 x11.6 4.92° 172 x5.8 9.76° 215 x4.7 12.13° 344 x2.9 18.98° 430 x2.3 23.27°
44 88 x11.4 5.03° 176 x5.7 9.98° 220 x4.5 12.41° 352 x2.8 19.39° 440 x2.3 23.75°
45 90 x11.1 5.14° 180 x5.6 10.20° 225 x4.4 12.68° 360 x2.8 19.80° 450 x2.2 24.23°
46 92 x10.9 5.26° 184 x5.4 10.43° 230 x4.3 12.95° 368 x2.7 20.20° 460 x2.2 24.70°
47 94 x10.6 5.37° 188 x5.3 10.65° 235 x4.3 13.22° 376 x2.7 20.61° 470 x2.1 25.17°
48 96 x10.4 5.48° 192 x5.2 10.87° 240 x4.2 13.50° 384 x2.6 21.01° 480 x2.1 25.64°
49 98 x10.2 5.60° 196 x5.1 11.09° 245 x4.1 13.77° 392 x2.6 21.41° 490 x2.0 26.10°
50 100 x10.0 5.71° 200 x5.0 11.31° 250 x4.0 14.04° 400 x2.5 21.80° 500 x2.0 26.57°
51 102 x9.8 5.82° 204 x4.9 11.53° 255 x3.9 14.31° 408 x2.5 22.20° 510 x2.0 27.02°
52 104 x9.6 5.94° 208 x4.8 11.75° 260 x3.8 14.57° 416 x2.4 22.59° 520 x1.9 27.47°
53 106 x9.4 6.05° 212 x4.7 11.97° 265 x3.8 14.84° 424 x2.4 22.98° 530 x1.9 27.92°
54 108 x9.3 6.16° 216 x4.6 12.19° 270 x3.7 15.11° 432 x2.3 23.36° 540 x1.9 28.37°
55 110 x9.1 6.28° 220 x4.5 12.41° 275 x3.6 15.38° 440 x2.3 23.75° 550 x1.8 28.81°
56 112 x8.9 6.39° 224 x4.5 12.63° 280 x3.6 15.64° 448 x2.2 24.13° 560 x1.8 29.25°
57 114 x8.8 6.50° 228 x4.4 12.84° 285 x3.5 15.91° 456 x2.2 24.51° 570 x1.8 29.68°
58 116 x8.6 6.62° 232 x4.3 13.06° 290 x3.4 16.17° 464 x2.2 24.89° 580 x1.7 30.11°
59 118 x8.5 6.73° 236 x4.2 13.28° 295 x3.4 16.44° 472 x2.1 25.27° 590 x1.7 30.54°
60 120 x8.3 6.84° 240 x4.2 13.50° 300 x3.3 16.70° 480 x2.1 25.64° 600 x1.7 30.96°
61 122 x8.2 6.96° 244 x4.1 13.71° 305 x3.3 16.96° 488 x2.0 26.01° 610 x1.6 31.38°
62 124 x8.1 7.07° 248 x4.0 13.93° 310 x3.2 17.22° 496 x2.0 26.38° 620 x1.6 31.80°
63 126 x7.9 7.18° 252 x4.0 14.14° 315 x3.2 17.48° 504 x2.0 26.75° 630 x1.6 32.21°
64 128 x7.8 7.29° 256 x3.9 14.36° 320 x3.1 17.74° 512 x2.0 27.11° 640 x1.6 32.62°
65 130 x7.7 7.41° 260 x3.8 14.57° 325 x3.1 18.00° 520 x1.9 27.47° 650 x1.5 33.02°
66 132 x7.6 7.52° 264 x3.8 14.79° 330 x3.0 18.26° 528 x1.9 27.83° 660 x1.5 33.42°
67 134 x7.5 7.63° 268 x3.7 15.00° 335 x3.0 18.52° 536 x1.9 28.19° 670 x1.5 33.82°
68 136 x7.4 7.74° 272 x3.7 15.22° 340 x2.9 18.78° 544 x1.8 28.55° 680 x1.5 34.22°
69 138 x7.2 7.86° 276 x3.6 15.43° 345 x2.9 19.03° 552 x1.8 28.90° 690 x1.4 34.61°
70 140 x7.1 7.97° 280 x3.6 15.64° 350 x2.9 19.29° 560 x1.8 29.25° 700 x1.4 34.99°
71 142 x7.0 8.08° 284 x3.5 15.85° 355 x2.8 19.54° 568 x1.8 29.60° 710 x1.4 35.37°
72 144 x6.9 8.19° 288 x3.5 16.07° 360 x2.8 19.80° 576 x1.7 29.94° 720 x1.4 35.75°
73 146 x6.8 8.31° 292 x3.4 16.28° 365 x2.7 20.05° 584 x1.7 30.28° 730 x1.4 36.13°
74 148 x6.8 8.42° 296 x3.4 16.49° 370 x2.7 20.30° 592 x1.7 30.63° 740 x1.4 36.50°
75 150 x6.7 8.53° 300 x3.3 16.70° 375 x2.7 20.56° 600 x1.7 30.96° 750 x1.3 36.87°

(Thanks to Telemeter user Andrej for this trick!)

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