Remote Health Monitoring for Asset Management

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12 53 TEMPERATURE (ºC) 10 8 6 4 2 0 -2 Ambient conditions Heat ‐ location A Heat ‐ Location B 48 43 38 33 28 TEMPERATURE (ºF) -4 -6 23 -8 0 50 100 150 200 HEIGHT (IN.) 18 Figure 5.15. Schematic diagram of test pile showing locations where heat was applied (top) and resulting temperature measurements along sensor array. The sound earth point and the transition area were further investigated by determining the standard deviation of the data measured from each sensor. The standard deviation is determined from the equation: ∑ 1 40
Where is the sample mean and n is the sample size. The standard deviation is a measure of how widely dispersed values are from the average. For sensors exposed to air, the measurements vary with the diurnal temperature variations, and as such the standard deviation is high. For sensors in sound earth, the temperature varies very little over time, such that the standard deviation would be expected to be low. To evaluate the behavior of the sensor array, data was examined under three conditions; the standard deviation over a 24 hour period, the average of 24 hr standard deviations over 1 week, and the standard deviations for 1 week of data. Figure 5.16 shows the standard deviation from the sensor array under each of the three conditions. Analysis of data in this manner reveals if such data analysis would be adequate over a short time period (24 hours), when ambient temperature variations may be small, as well as over a longer time period (1 week) when ambient temperature variations would be expected to be larger. For evaluation of the effects of scour, a shorter time period is desired, such that rapid notification of a change in condition at the pile site would be feasible. STANDARD DEVIATION (ºC) 7 6 5 4 3 2 1 Typical 24 hrs Average - 24 hrs 7 - day period 12 10 8 6 4 2 STANDARD DEVIATION (ºF) 0 0 50 100 150 200 HEIGHT (in.) Figure 5.16. Standard deviation of temperature outputs for three time intervals: 24 hr. period, average of 24 hr. periods for 7 days, and standard deviation over a 7 day period. 0 Figure 5.17 shows the average standard deviations for the 24 hr periods, as well as the standard deviation of those results, to indicate the scatter between separate 24 hr periods. As the figure indicates, the dispersion of standard deviations is higher for the sensor in air and in the transition region relative to those sensors in sound earth. The results shown in this figure indicate that examining the standard deviations may provide a robust tool for estimating the height of sound earth along the pile. The standard deviations for three sensors are shown in Table 1. This 41
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Page 3 and 4: FINAL REPORT RI07-002 Remote Health
Page 5 and 6: List of Figures Figure 2.1. Photogr
Page 7 and 8: Executive Summary This project expl
Page 9 and 10: States as a means of technology tra
Page 11 and 12: where the soil / water interface ex
Page 13 and 14: from a sensor, the micro-controller
Page 15 and 16: solder connections, simplify manufa
Page 17 and 18: Figure 3.5. Photonegative used for
Page 19 and 20: temperature changes that could be m
Page 21 and 22: Figure 3.11. Diagram of the 48 in.
Page 23 and 24: Two ceramic heatplates were used to
Page 25 and 26: stores the data at a specified rate
Page 27 and 28: TEMPERATURE(°C) 60 50 40 30 20 10
Page 29 and 30: 45 109 TEMPERATURE (ºC) 40 35 30 2
Page 31 and 32: 50 TEMPERATURE ( F) 50 55 60 65 70
Page 33 and 34: 5 Field Implementation of Technolog
Page 35 and 36: the array after the epoxy has been
Page 37 and 38: 33 91 31 TEMPERATURE (ºC) 29 27 25
Page 39 and 40: Figure 5.8. 3-D graph showing senso
Page 41 and 42: interval. A time interval of 15 min
Page 43 and 44: 5.13, a portion of the pile is inst
Page 45: several days. Temperatures increase
Page 49 and 50: The data can also be observed as a
Page 51 and 52: to select a different time period f
Page 53 and 54: 6 Conclusions This research has exp
Page 55 and 56: REFERENCES 1. Richardson, E.P.-O.,

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