Meter Measurement Device - Lab Report Example

Laboratory 1: Micrometer Measurement Report Student Name: Student Registration No.: Course: University: Lecturer: Submission Date: Introduction Different measuring situations require different measuring devices to measure varying features for diverse sizes of equipment. Therefore, for any given size and shape of a component there is a measuring equipment used to determine the component dimensions. However, some measuring tools tend to have errors, which are because of human observations. Thus, these tools will require calibration to allow for accuracy of data measurement. A micrometer, on other occasions, is called a micrometer screw gauge; it is a device integrating a calibrated screw on the larger extent it is used in machining and mechanical engineering when precise measurements are needed. Usually, but not all occasions Micrometers are in the form of calipers where the opposing ends are joined by one frame. However, in the digital micrometer, the spindle screw is machined to provide very accurate measurements and the component whose dimensions will be determined is placed between the anvil and the spindle (Robert, and Paulo, 2011, 200). Turning the ratchet knob it moves the spindle until both the anvil and spindle lightly touch the object to be measured. Operating principle Micrometers employ the screw principle to us magnify small measurements (very small distances for direct measurement) into large measurements of the screw that are big and legible in a scale (Curtis, 2013, 566). The precision of a micrometer comes from the exactness of the thread-forms within the micrometer gauge. In other cases, it is known as differential screw. Basically, the micrometer uses the following operating principles: a. If the screw is accurately calibrated, it is easy to correlate the amount of rotation to made by the screw to the axial movement and the opposite is true, which moves through a constant known as screw lead. Screw lead is a distance made axially when a micrometer rotates in one complete 3600 turn. b. With a proper major and lead screw diameter, a certain amount of axial motion will be magnified in the leading circumferential motility. 1. Measurement using a digital micrometer A batch of pins with the dimensions shown in figure 1 below is to be produced. Randomly 30 samples were selected to measure critical dimensions, which were evaluated against tolerance requirements. Figure 1: sample specimen dimensions Procedure Step1: we randomly selected a pin for the box, measured the two critical dimensions 5 times; Step2: From the box containing the aluminium test specimens shown below, we randomly took 15 specimens and placed them in the wooden rack provided. Figure 2: aluminium test specimen Figure 3: Wooden box for placing the specimens Step3: Using the digital micrometer we measured the length and diameter of each test specimen as accurately as possible and recorded the measurement results; Step4: Remove the pins, and randomly take another 15 specimens and place them in the wooden rack. Step5: Repeat Step 3 Results and Discussion Three columns A, B and C of test specimens with each column having five specimens. We measure diameter and length for each specimen used in this experiment as they are arranged in the columns. To acquire accurate measurements from the specimen, a digital micrometer with 25mm and 50mm, minimum and maximum measurements is the desirable tool used to measure the specimen size (see figure 4 below). Figure 4: 25 to 50 mm micrometer Before starting the measurements for the dimensions, it is necessary to ensure that the micrometer-measuring gauge is reading zero this is important to ensure that there are no errors made in measuring the specimen to start at 25mm. Figure 5: micrometer-measuring gauge On ensure that the specimen is set in the micrometer, we tied the scroll knob until the reading was 25mm then presses set on the micrometer. Having set the micrometer and fitting the specimen, we measured the lengths and noted the results for the specimens for each column. The same measurement procedure was repeated for the same specimen but a different micrometer with measurement of 0 to 25 mm was used (fig below 6). Figure 6: 0 to 25 mm micrometer The measurement procedure for length measurement was repeated using the above micrometer, observations were made, and results recorded lengths and diameters of the specimens. All the data recorded for the specimen’s lengths and diameters were recorded in the table below. Table 1: data recorded using Micrometer   Column A   Column B   Column C Specimen X-Axis Y-Axis Specimen X-Axis Y-Axis Specimen X-Axis Y-Axis 1 5.053 27.544 11 5.047 27.526 21 5.059 27.516 2 5.062 27.518 12 5.060 27.429 22 5.057 27.527 3 5.074 27.462 13 5.031 27.456 23 5.057 27.439 4 5.060 27.447 14 5.058 27.408 24 5.066 27.513 5 5.059 27.526 15 5.077 27.479 25 5.059 27.512 6 5.082 27.340 16 5.058 27.481 26 5.051 27.461 7 5.067 26.278 17 5.063 27.432 27 5.075 27.507 8 5.050 27.361 18 5.071 27.520 28 5.061 27.216 9 5.058 27.525 19 5.073 27.517 29 5.065 27.459 10 5.065 27.428 20 5.057 27.448 30 5.059 27.377 Mean 5.063 27.343   5.060 27.470   5.061 27.453 Range 0.032 1.266 0.046 0.118 0.024 0.311 We calculated mean and range for all the tests using the data collected. We added all Y-axis and X-axis measurements and divided by 10 for each column to find the mean value. On the other hand, we subtracted minimum value from the maximum value for each column to find the range. However, there are uncertainties that may have occurred during the experimental procedures. Therefore, there was a need to calculate the mean value for both Y-axis and the X-axis to determine the accuracy of the measurements. Moreover, the range value, which is the difference between the maximum and the minimum value, measures the amount of error in the experimental results. Thus with the range value it is easy to determine the amount of discrepancy that exist between the accurate value and the measured value. One of the main reasons why we determine the mean value from an experiment is to determine which value is more accurate from the data collected while range it calculated to find the amount error that exist between the true and measured value in a data set (Dale, and Nelson, 2014, 181). When measurements are made using micrometers, the data must show repeatability and consistency, which means the data, is most accurate. From the data collected in table 1 column B has mean x-axis of 5.060 and range of 0.046, this means that to find the accurate value there is ± of the range. Thus, if the range small repeatedly the associated value is more accurate. 2. Digital Vanier calipers A V-block is measured in this section. Figure 7: Veeblock Assembly First, we needed to separate all the components to get every component of the V-bock we had to separate the model to get each component alone V-block (see fig 8 below). Figure 8: Separated components of a Veeblock Secondly, we needed to use a Vanier calipers to measure the exact dimensions of the component. Figure 9: Digital Vanier Calipers Most accurate external and internal data for a complex component are collected using digital Vanier calipers. When measuring readings using the Vanier calipers, the Vanier scale is set to zero. Measurements are indicated in screen in the Vanier calipers that show the measured values. To get accurate readings, the digital Vanier calipers is set to zero. The lower jaw is used to measure external features while the lower jaw is used to measure the internal features. When adjusting the calipers for accurate measurement the roller on the lower side is adjusted. 3. Measurement using coordinate Measuring Machine (CMM) In this experiment, Kemco Kadet Coordinate Measuring Machine (CMM) was used to measure the dimensions. This program is installed on the computers in CNC laboratories and we used the computers for measurements (see figure 9). Figure 10: coordinate Measuring Machine (CMM) The procedure used to measure the component using the machine was as outlined below: a. To start, we placed the component on the machine table then run the program from the computer, which is procedurally set according the required number of points that will be measured. b. The machine is allowed to determine the X,Y, and Z- axis then touches the edges of the component. to allow the machine to identify the X, Y and Z-axis, touch the edges. Sequentially, the machine is run to measure the component length and width by only touching the machine edge and head of the pointer needle to the number of points specified for the component. Figure 11: CMM measuring tool c. Following the guide program, we measured all the pockets and holes on the component. d. We then used the digital micrometer to measure the spherical holder dimensions since the machine was not able to measure dimensions of a spherical shape. e. Using the program options in the program menu we generated excel sheet, which had the measurements for the component tabulated in table 2 below. CMM-Manager Report Part Name Part To Measure Date Thursday, February 19, 2015 Time 1:11 PM Unit MM Left_Face X -0.023 A/X 90°0'2" L 63.151     Y 11.458 A/Y 0°0'2"         Z -0.003 A/Z 90°0'0" F 0.005     Rear_Face X 13.826 A/X 0°0'30" L 113.890     Y 89.233 A/Y 89°59'30"         Z 0.005 A/Z 90°0'0" F 0.011     Right_Face X 139.161 A/X 90°1'6" L 44.602     Y 84.534 A/Y 0°1'6"         Z 0.012 A/Z 90°0'0" F 0.002     ARC_Front_Right X 106.357     R 32.831     Y 32.831     A 56°1'11"     Z 0.005     F 0.005     Front_Face X 94.954 A/X 0°0'34" L 86.793     Y -0.010 A/Y 89°59'26"         Z 0.002 A/Z 90°0'0" F 0.007     Slot_X_Y_Midpoint_L-Length_W-Width X 27.661 A/X 35°59'22" L 52.446     Y 23.997 A/Y 125°59'22" W 15.947     Z 0.000 A/Z 90°0'3" F 0.043     Depth_Of_Slot_Z X 0.000             Y 0.000             Z -13.958             Pocket_X_Y-Midpoint_L-Length_W-Width X 60.738 A/X 0°1'1" L 26.457     Y 45.422 A/Y 89°58'59" W 31.802     Z 0.004 A/Z 89°59'50" F 0.019     Depth_Of_Pocket_Z X 0.000             Y 0.000             Z -15.973             Circle_Left_Rear X 24.320     R 9.955     Y 66.607     D 19.911     Z 0.004     F 0.016     Depth_Of_Circle_Rear_Z X 0.000             Y 0.000             Z -17.844             Circle_Right_Front X 106.149     R 12.454     Y 32.175     D 24.908     Z 0.005     F 0.003     Depth_Of_Circle_Right_Front_Z X 0.000             Y 0.000             Z -9.933             Bolt_hole_1 X 104.344     R 3.006     Y 53.082     D 6.013     Z 0.007     F 0.022     Bolt_hole_2 X 123.299     R 3.010     Y 44.162     D 6.020     Z 0.007     F 0.046     Bolt_hole_3 X 125.140     R 3.007     Y 23.275     D 6.014     Z 0.005     F 0.009     Bolt_hole_4 X 107.941     R 3.009     Y 11.293     D 6.017     Z 0.003     F 0.006     Bolt_hole_5 X 88.951     R 2.991     Y 20.180     D 5.983     Z 0.003     F 0.031     Bolt_hole_6 X 87.161     R 3.027     Y 41.001     D 6.054     Z 0.005     F 0.006     Depth_Of_Bolt_hole_Z X 0.000             Y 0.000             Z -21.709             Circle_Right_Rear X 119.422     R 3.005     Y 74.725     D 6.010     Z 0.000     F 0.005     Depth_Of_Circle_Right_Rear X 119.447             Y 73.621             Z -17.896             Thickness_Touch_On_Granite_Table X 0.000             Y 0.000             Z -38.915             Table 2: CMM manager report f. We then exported the data to excel sheet and used the data in CAD SolidWrks to prepare the component see Export the excel sheet data and then use the important data to prepare a SolidWorks CAD component (see fig below). Figure 12: CMM SolidWorks component g. Using BS888 third angle projection, we produced a fully dimensioned component diagram. Using the measurements from the CMM machine, we drew a complete diagram in SolidWorks (see figure below). Figure 13: Fully dimensioned component from CMM measurements Since CMM is automated to generate measurements, it has the ability to capture even the minor detailed reading of the component. One of the major advantages of using CMM is that, the measurements are computer generated hence there are no human errors like other methods of measurements. Additionally, when using the data collected by CMM, there is no need to calibrate the system to fit the desired features since the data from CMM is consistent and repeats for every component made using the machine. References Dale, E. and Nelson, C., 2014, Elementary Technical Mathematics. New York: Cengage Learning. Robert, J. H., and Paulo, H. P., 2011, Coordinate Measuring Machines and Systems, Second Edition. New York: Cengage Learning. Curtis, M., 2013, Handbook of Dimensional Measurement. New York: Industrial Press. Read More

Figure 1: sample specimen dimensions Procedure Step1: we randomly selected a pin for the box, measured the two critical dimensions 5 times; Step2: From the box containing the aluminium test specimens shown below, we randomly took 15 specimens and placed them in the wooden rack provided. Figure 2: aluminium test specimen Figure 3: Wooden box for placing the specimens Step3: Using the digital micrometer we measured the length and diameter of each test specimen as accurately as possible and recorded the measurement results; Step4: Remove the pins, and randomly take another 15 specimens and place them in the wooden rack.

Step5: Repeat Step 3 Results and Discussion Three columns A, B and C of test specimens with each column having five specimens. We measure diameter and length for each specimen used in this experiment as they are arranged in the columns. To acquire accurate measurements from the specimen, a digital micrometer with 25mm and 50mm, minimum and maximum measurements is the desirable tool used to measure the specimen size (see figure 4 below). Figure 4: 25 to 50 mm micrometer Before starting the measurements for the dimensions, it is necessary to ensure that the micrometer-measuring gauge is reading zero this is important to ensure that there are no errors made in measuring the specimen to start at 25mm.

Figure 5: micrometer-measuring gauge On ensure that the specimen is set in the micrometer, we tied the scroll knob until the reading was 25mm then presses set on the micrometer. Having set the micrometer and fitting the specimen, we measured the lengths and noted the results for the specimens for each column. The same measurement procedure was repeated for the same specimen but a different micrometer with measurement of 0 to 25 mm was used (fig below 6). Figure 6: 0 to 25 mm micrometer The measurement procedure for length measurement was repeated using the above micrometer, observations were made, and results recorded lengths and diameters of the specimens.

All the data recorded for the specimen’s lengths and diameters were recorded in the table below. Table 1: data recorded using Micrometer   Column A   Column B   Column C Specimen X-Axis Y-Axis Specimen X-Axis Y-Axis Specimen X-Axis Y-Axis 1 5.053 27.544 11 5.047 27.526 21 5.059 27.516 2 5.062 27.518 12 5.060 27.429 22 5.057 27.527 3 5.074 27.462 13 5.031 27.456 23 5.057 27.439 4 5.060 27.447 14 5.058 27.408 24 5.066 27.513 5 5.059 27.526 15 5.077 27.479 25 5.059 27.512 6 5.082 27.340 16 5.058 27.481 26 5.051 27.461 7 5.067 26.278 17 5.063 27.432 27 5.075 27.507 8 5.050 27.361 18 5.071 27.520 28 5.061 27.216 9 5.058 27.525 19 5.073 27.517 29 5.065 27.459 10 5.065 27.428 20 5.057 27.448 30 5.059 27.377 Mean 5.063 27.343   5.060 27.470   5.061 27.453 Range 0.032 1.266 0.046 0.118 0.024 0.311 We calculated mean and range for all the tests using the data collected.

We added all Y-axis and X-axis measurements and divided by 10 for each column to find the mean value. On the other hand, we subtracted minimum value from the maximum value for each column to find the range. However, there are uncertainties that may have occurred during the experimental procedures. Therefore, there was a need to calculate the mean value for both Y-axis and the X-axis to determine the accuracy of the measurements. Moreover, the range value, which is the difference between the maximum and the minimum value, measures the amount of error in the experimental results.

Thus with the range value it is easy to determine the amount of discrepancy that exist between the accurate value and the measured value. One of the main reasons why we determine the mean value from an experiment is to determine which value is more accurate from the data collected while range it calculated to find the amount error that exist between the true and measured value in a data set (Dale, and Nelson, 2014, 181). When measurements are made using micrometers, the data must show repeatability and consistency, which means the data, is most accurate.

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