Download presentation

Presentation is loading. Please wait.

Published byKiana Tallon Modified over 2 years ago

1
1 Pace - Is the measure of a full stride from the position of the heel when it is raised from the ground to the point the same heel is set down again at the end of the step. Thus, a distance can be "paced off" by counting each time the same heel touches ground, or in other words, every other step. In Rome this unit was standardized as five Roman feet (about 1.48 meters or 58.1 English inches). Today, a pace is one step and a stride is two steps Distance Measurement Introduction – Today we will begin to move from approximate forms of measurement to more precise forms.

2
2 Pacing zThe ability to pace distance is very useful when no greater than 2% accuracy is required. zA person can determine their pace by counting the number of paces necessary to walk a distance that has been previously measured zA pace is defined as one step zA stride is consider two steps Activity: Pacing Exercise Distance Measurement

3
3 Chaining zFor centuries engineers have measured distances with ropes, lines, or cords zThe term chaining is a carry–over from the time when the Gunter chain was used (1600’s) zThe 66 foot chain is made of 100 links 7.92 inches in length zIn 1785 U.S. a federal law stated that all government surveys must be done with a Gunter's chain Distance Measurement

4
4 zIt lies at the origin of the definition of an acre. zThe original acre was an area of land suitable for ploughing with a defined amount of work (e.g., ten furrows long, each furrow being ten chains, permitting rests of an oxen team) zIt measured one chain by one furlong (totaling 10 square chains). zEarly two–lane roads were laid out with a chain, resulting in a 66– ft right–of–way Chaining Distance Measurement

5
5 Taping zTapes are available in lengths up to 1,000 feet; precision of 0.005 feet (<.5%) can be obtained if used properly. Distance Measurement Activity: Taping vs. Pacing Exercise

6
6 Taping over Level Ground zIf the taping is done over level ground where there is no underbrush, the tape can rest on the ground zA taping crew consists of two people: the head tapeperson and the rear tapeperson zThe head tapeperson takes one end of the tape walks down the line towards the point zIf the distance is more than 100 ft, then the head tapeperson places a taping pin at the 100 ft interval and the process is repeated Distance Measurement

7
7 Measuring Wheels/ Odometers Activity: Measuring Wheels vs. Pacing Exercise Distance Measurement On smooth surfaces, odometers are accurate to within 1% Difficult to use on rough ground or through heavy vegetation

8
8 Electronic Distance Measurement (EDM) zEDMs are very useful in measuring distances that are difficult to access or long distances Distance Measurement

Similar presentations

OK

Unit 8 - Use of Maps John Guthrie, USGS. Unit 8 - Use of Maps Demonstrate the ability to shoot a bearing (azimuth) off a compass Explain the importance.

Unit 8 - Use of Maps John Guthrie, USGS. Unit 8 - Use of Maps Demonstrate the ability to shoot a bearing (azimuth) off a compass Explain the importance.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google