Theory and Design for Mechanical Measurements
6th Edition
ISBN: 9781118881279
Author: Richard S. Figliola, Donald E. Beasley
Publisher: WILEY
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Chapter 8, Problem 8.6P
An RTD forms one arm of a Wheatstone bridge, as shown in Figure 8.44. The RTD is used to measure a constant temperature with the bridge operated in a balanced mode. The RTD has a resistance of 100 Q at a temperature of 0 °C, and a thermal coefficient of resistance, a = 0.003925 °C-1. The value of the variable resistance R}must be set to 171 Q to balance the bridge circuit.
- Determine the temperature of the RTD.
- Compare this circuit to the equal-arm bridge in Example 8.2. Which circuit provides the greater static sensitivity?
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A strain gauge is used to measure the tension force in a 2-cm diameter bar of steel with Young modulus of 2.07 x 107 N/cm2 (30 x 106 lb./in.2). The strain gauge has a nominal resistance of 160 Ω and a GF of 5. The gauge is connected to a bridge supplied with a 10 Vdc. The bridge was initially balanced. After the bar is put under tension, the bridge output voltage is 0.0008 Vdc.
Draw the schematic of the bridge (setup).
Calculate the force on the bar.
A J-type thermocouple is used to measure the unknown steady-state temperature of a
liquid. The sensor outputs a voltage of 2.532 mV. Using Equation 2 and Table 1.2,
determine the unknown temperature. Show all calculations and assume the
thermocouple is referenced to 0 °C.
T = a₁ + a₂V + ·
...+ a₂V²
a
a₁
0.000 000
1.978 425 x 10-²
-2.001 204 x 10¹7
1.036 969 x 10-¹1
-2.549 687 x 10-16
3.585 153 x 10-21
-5.344 285 x 10.26
5.099 890 x 10:³1
Table 1.2 -J-type thermocouple polynomial coefficients over the range of 0°C to 760°C ± 0.04°C
8₂
a3
a4
(2)
as
as
a7
1- A J-Type thermocouple
referenced to 80°F has a
measured output emf of 2.878
mV. What is the temperature of
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Chapter 8 Solutions
Theory and Design for Mechanical Measurements
Ch. 8 - Prob. 8.1PCh. 8 - Fixed temperature points in the International...Ch. 8 - Answers to the following questions may be found in...Ch. 8 - Calculate the resistance of a platinum wire that...Ch. 8 - Plot the resistance of a platinum wire that is 5 m...Ch. 8 - An RTD forms one arm of a Wheatstone bridge, as...Ch. 8 - An RTD forms one arm (/?4) of a Wheatstone bridge,...Ch. 8 - Research and describe current state-of-the-art...Ch. 8 - Prob. 8.9PCh. 8 - 8.10 Estimate the required level of uncertainty in...
Ch. 8 - 8.11 A thermistor is placed in a 100 °C...Ch. 8 - Prob. 8.12PCh. 8 - Prob. 8.13PCh. 8 - The thermocouple circuit in Figure 8.45 represents...Ch. 8 - The thermocouple circuit in Figure 8.45 represents...Ch. 8 - The thermocouple circuit in Figure 8.45 is...Ch. 8 - 8.17 a. The thermocouple shown in Figure 8.46a...Ch. 8 - Prob. 8.18PCh. 8 - Prob. 8.19PCh. 8 - A temperature measurement requires an uncertainty...Ch. 8 - A temperature difference of 3.0 °C is measured...Ch. 8 - Complete the following table for a J-type...Ch. 8 - Complete the following table for a T-type...Ch. 8 - Prob. 8.24PCh. 8 - 8.25 You are employed as a heating, ventilating,...Ch. 8 - A J-type thermocouple for use at temperatures...Ch. 8 - A J-type thermocouple is calibrated against an RTD...Ch. 8 - A beaded thermocouple is placed in a duct in a...Ch. 8 - Consider a welded thermocouple bead that...Ch. 8 - Prob. 8.30PCh. 8 - Prob. 8.31PCh. 8 - Consider the typical construction of a sheathed...Ch. 8 - An iron-constantan thermocouple is placed in a...Ch. 8 - Figure 8.48 Schematic diagram for Problems 8.33,...Ch. 8 - Figure 8.48 Schematic diagram for Problems 8.33,...Ch. 8 - 8.36 In Example 8.5, an uncertainty value for Rf...Ch. 8 - The thermocouple circuit shown in Figure 8.49...Ch. 8 - Prob. 8.38PCh. 8 - 8.39 A thin-film heat flux sensor employs a K-type...Ch. 8 - A thin-film heat flux sensor has a sensitivity uV...Ch. 8 - 8.41 A T-type thermopile is used to measure...Ch. 8 - 8.42 A T-type thermocouple referenced to 0 °C is...Ch. 8 - A T-type thermocouple referenced to 0 °C develops...Ch. 8 - 8.44 A temperature measurement system consists of...
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- A thermocouple is used to measure the temperature T1. The thermocouple reference junction labeled 2 is at a temperature of 20°C. The voltage output is measured using a potentiometer and found to be 4.686 mV. What is T1 in degrees RK: if the temperature values are not in the table, you have to use interpolation. Select one: O a. 98 O b. 118 O c. 105 O d. 108 Previous page Next pagearrow_forwardWhat is the resistance of gauge no. 10 copper wire (diameter of 0.026 m), which is 1km long at 20 degrees Celcius?arrow_forwardPart (A) A strain gauge and bridge circuit are used to measure the tension force in a bar of steel that has a cross-sectional area of 13 cm.The strain gauge has a nominal resistance of 120 0 and a GF of 2. The bridge is supplied with 10 V. When the bar is unloaded, the bridge is balanced so 2-in. cross-sectional area 4120 a the output is oV. Then force is applied to the bar, and the bridge voltage goes to 0.0005V. Find the force on the bar. V 0.000s v 20 a 10 V 6000 Part (B)f we assume Simple resistance bridge arrangement as shown in the fgure below for strain measurement, colculate the change in output voltage, if exctng voltnge is 9.5 V and we have the value of AR/R as per the dats given in part (a). く)arrow_forward
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