Theory and Design for Mechanical Measurements
6th Edition
ISBN: 9781118881279
Author: Richard S. Figliola, Donald E. Beasley
Publisher: WILEY
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Textbook Question
Chapter 8, Problem 8.21P
A temperature difference of 3.0 °C is measured using a thermopile having three pairs of measuring junctions, arranged as shown in Figure 8.23.
a. Determine the output of the thermopile for J-type thermocouple wire, if all pairs of junctions sense the 3.0 °C temperature difference. The average temperature of the junctions is 80 °C.
b. If the thermopile is constructed of wire that has a maximum emf variation from the NIST standard values of ±0.8% (95%), and the voltage measuring capabilities in the system are such that the uncertainty is ±0.0005 V (95%), perform an uncertainty analysis to estimate the uncertainty in the measured temperature difference at the design stage.
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Students have asked these similar questions
If the observed voltage given by a
thermocouple of type K equals to 72.5 mV
then for an amplification factor of 40 the
actual voltage is:
Select one:
a. 0.0018125 mV.
b. 0.0018125 V.
c. 2.9 mV.
d. 0.029 V.
PROBLEM 4: (See example 8.6)
A J-type thermocouple is used to measure an unknown temperature. The reference junction, T2, is at 71 F. The voltmeter reads 18.743 mV. What is the T1 junction temperature?
3. A RTD forms one arm of a Wheatsone bridge, as shwon in Figure 1. The RTD is used to measure
a constant temperature, with the bridge operated in a balanced mode. The RTD has a resistance of
252 at a temperature of 0°C, and a thermal coefficient of resistance, a = 0.003925°C''. The value
of the variable resistance R, must be set to 41.4852 to balance the bridge circuit, with the RTD in
thermal equilibrium with the measuring environment. Determine the temperature of the RTD.
R;= Ry= 100 0
R- 25 a at
oc and balanced
bridge conditions
RTD
Figure 1: Wheatstone bridge circuit
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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