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Unformatted text preview: LABORATORY EXERCISE # 01 TAPE STANDARIZATION AND ESTABLISHING PACE
OBJECTIVE: Familiarization with equipment utilized in this laboratory exercise. Demonstrate the method to standardize a tape and practice it. Establish your pace on level ground. EQUIPMENT:
1. 2. 3. 4. 100’ steel tape 2 plumb bobs in leather pouches hand level in leather case tension scale and FIELD PROCEDURE:
TEMPERATURE READINGS Before starting the lab exercise and after completing the exercise, note the temperature on the thermometer mounted above the back door of BRAE Room 122 on the outdoor side of the wall. Record these temperatures in your field book as noted in the example field notes for this lab exercise shown on the next page. I. STANDARDIZATION OF STEEL TAPE 1. Carefully unroll the tape completely from the reel. 9 10 0FEET 2. Align the 100’-mark on the tape precisely over the line on the monument. (The sketch is shown for the purpose of identifying the 100.00 mark and the correct mark on the monument only.) 3. Attaching the tension scale to the leather strap at the zero end of the tape, pull the tape with 10 lbs. of tension with the tape fully supported on the ground and note the zero alignment on the monument. a. If the zero is between the two monuments, the tape is short. b. If the zero is outside of the two monuments, the tape is long. 100' End of Tape 100' End of Tape 0 0 S HORT LONG 4. Note how much the tape is short or long and record the measured length using the format shown in the example field notes for this exercise. Rev. July 2010 Page 9 Lab Ex. #01 – Standardizing a Tape and Establishing your Pace II. ESTABLISHING UNSUPPORTED PULL 1. Now move tape to two nails approximately 100’ apart. Measure the distance on the ground using 10 lb. pull. Record the distance. Now lifting the tape off the nails on both ends, use plumb bobs and determine the tension required to maintain the same length of tape as was obtained when the tape was fully supported. 2. Record this information as shown in the example field notes. III. DETERMINATION OF INDIVIDUAL PACE 1. With your toe lined adjacent with one of the monument standards, step naturally toward the other monument standard counting the number of steps required. 2. Do this procedure three times recording each as shown in the field book example. IV. SKETCH OF THE AREA 1. Prepare a detailed sketch of the area showing the following: a) General area b) Location and description of standards and nails used c) Swing ties to standard and nails. d) Note the Direction based on your compass reading of the seam between the concrete and the asphalt. OFFICE PROCEDURE:
1. Record the pacing information in your field book for each person in your party. 2. Calculate your pace to the nearest 0.1 foot by dividing the average number of steps taken into 100 feet. 3. Again record the answer and show an example calculation following the field book example. 4. Be sure all information requested on the score sheet has been clearly shown in the field book. Turn in book by the deadline and at the location specified by the instructor. 5. The layout of the exercise and how the data is to be recorded in your field book is shown on the next page. Follow the format given carefully. Be sure that you record the data actually measured and not use the example information. Page 10 Rev. July 2010 Lab Ex. #01 – Standardizing a Tape and Establishing your Pace Rev. July 2010 Page 11 Lab Ex. #01 – Standardizing a Tape and Establishing your Pace LAB 1 – Additional Computations (If directed by your Instructor) Based on the results from your standardization of the tape perform the following Calculations: You are theoretically determining the area of triangle A-B-C, by measuring the base and the height of the triangle. The base was theoretically measured twice and the height measured once (as a horizontal distance using standardized pull) based on the following data CREW No. 1 2 3 4 5 6 7 8 9 10 Measured Base (ft) in - out 553.76 – 553.70 642.78 – 642.84 489.76 – 489.68 596.33 – 596.41 438.19 – 438.13 517.68 – 517.75 608.00 – 607.94 466.82 – 466. 89 537.27 – 537.22 627.45 – 627.52 Measured Height (ft) 123.45 108.56 167.89 117.63 203.56 134.96 146.37 124.75 126.53 105.19 Temp (F) 96° 87° 103° 91° 105° 45° 37° 23° 42° 33° At the end of your Lab 1 Field notes (After your sketch) continue on these calculations as a part of Lab 1; determining the following, showing your calculations and answers: 1. 2. Average distance of the measured base Ratio of Error for the Base distance measurements Ratio of Error 3. out - in Average Distance 1 X Corrected Length for the average Base a. Using the average base distance correct for; i. Temperature using the average of the temperature you recorded for lab 1 as the Standard Temperature Ts and the temperature in the table above for T C t 0.00000645(T Ts ) L
ii. Length using the Standardized length of your tape based on Lab 1 LengthCorrected Page 12 LengthS tan dard LengthMeasured 100.00 Rev. July 2010 Lab Ex. #01 – Standardizing a Tape and Establishing your Pace 4. 5. Corrected Length for the Height a. Correcting for both Temperature and Standard Length as described in 3 above Area of the Triangle in square feet and in acres a. AreaTriangle 1 Base Height 2 b. (43,560 sq. ft = 1 acre). 6. The area of the triangle using only the measured values a. Uncorrected values 7. The difference in Square feet between the corrected area and uncorrected area Sample Calculations Crew “A” measured 100.03’ on the standard @ 66°F, therefore the tape length = 99.97’ In the table on the previous page, crew “A” had the following values Measured Base In = 701.56 Out = 701.66 Measured Height = 215.53 Temp (F) = 39° 1. Average Distance for the Measured Base 701.56 701.66 701.61 . 2 2. Ratio of Error for the Base Distance measurement 1 701.56 701.66 0.000142529 .. 7000 701.61 3. Corrected Length for the average Base 0.00000645 39° 66° 99.97 0.0174 Tape Length @ 99° 99.97‐0.0174 99.953’ 99.953 701.61 701.28′ 100.00 4. Corrected Length for the Height. Note Tape length @ 99° is same as shown above 99.953 215.53 215.43 100.00 5. Area of the triangle in square feet and acres 1 2 701.28 215.43 75,538 . . 1.734 6. Area of the triangle using the original measured values 1 2 701.61 215.53 75,609 . . 1.736 7. The difference in square feet between corrected and uncorrected areas |75538 75609| 71 Rev. July 2010 Page 13 Lab Ex. #01 – Standardizing a Tape and Establishing your Pace NOTES: Page 14 Rev. July 2010 ...
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- Winter '10