Wndsn Quadrant Telemeters
Description and use.
The Wndsn Quadrant Telemeter is a simple observational tool for measuring angles via various inputs combined with a number of means to directly process the acquired values.
One important thing to remember is that you won't typically be using the Quadrant Telemeter from ground level, but at eye level. So when taking slope or grade measurements, make sure to aim the sights at the equivalent "eye level" height on the object you are sighting - or take the reading directly from ground level. Using the Telemeter scale on the front side of the instrument, we can ignore the difference and point directly at the baseline, provided we are on an equal level.
Improving accuracy of reading
- Always make an estimation and an approximation, at least of the order of magnitude expected.
- Instead of attempting to read the exact value, which may be obscured by the string, establish the range of values the measurement is between. By "bracketing" the measurement in such a way, we can achieve higher accuracy by exactly determining what our value is not.
Be careful not to lose or distort data (as in measurement results or string positions) while switching between Telemeter front- and backside, transposing measuring or computation results. A small notebook is of great help here.
Improving accuracy of measurement
While the device precision is dependent on the scales, the accuracy of reading is dependent on external factors, some of which are controllable to an extent.
Reading accuracy may be affected by light and atmospheric conditions like mirage around the object to be measured, as well as factors that prevent steady scales for a reliable read.
- Make sure that the length of the string translates to as exact the distance of 57.3 cm (22.56 inches) from eye to scale as possible.
- Find as large an object as possible to measure.
- Make sure to have a good contrast and visibility of the features of the object to be measured.
- To steady the scales, eliminate as many external influences as possible to each measurement.
- Get a stable rest for the holding hand.
- Take the measurement (for the Telemeter side) as perpendicular as possible to the object measured.