Part V: Distance Measurement-Horizontal Distance from \"E\" to \"F\": Since the
ID: 1712471 • Letter: P
Question
Part V: Distance Measurement-Horizontal Distance from "E" to "F": Since the EDM on your total station has quit working and you have a steel tape in the truck, you must go ahead and pull tape to determine the horizontal distance between “F” and “F”. Since the terrain is very level as checked by your hand level, you are only required to adjust your measurement for temperature which is 104° F at the time of measurement. (The tape was standardized at 68° F with a length of 10000 ft.). Your measured distance was 78654 ft. What is 93 the true distance of the line “EFin US Survey Feet?Explanation / Answer
When measuring distances,standard temperature of the tape is different from temperature of the tape during measurement.Due to temperature,the length of the tape will vary(it may be long or it may short).A correction for temperature is applied to the tape.It is given by
Ct = C x L x (Tm - Ts)
Given data :
C = Coefficient of thermal expansion of steel = 9.6 X 10-6 inch / inch /deg F
L = Length of the horizontal line measured = 786.54 ft = 9438.48 inches
Tm = Observed temperature of the tape at the time of measurement = 1040 F
Ts = Standard temperature of the tape = 680 F
Ct = Correction to be applied to the tape due to temperature
Ct = 9.6 X 10-6 X 9438.48 X ( 104 - 68) = 3.26
The correction Ct is added to L to obtain the corrected distance or true distance (d).
Therefore, d = L + Ct = 9438.48 + 3.26 = 9441.74 inches = 786.8 ft
Therefore ,true distance of the line EF = 786.8 ft