Measurement technology textbook problems

AI Thread Summary
The discussion focuses on various measurement technology problems, including the Wheatstone bridge circuit and its balance condition, the operating principles of a strain gauge, and the application of the Aron connection for three-phase power measurement. Participants explore the active, reactive, and apparent power consumption calculations, as well as resistance measurement using the V-A method, emphasizing circuit configurations that minimize systematic errors. The accuracy of different voltmeters for measuring DC voltage is analyzed, with calculations to determine the most precise instrument. Additionally, the discussion covers waveform analysis from an oscilloscope, identifying measurable quantities and phase differences. Overall, the thread emphasizes problem-solving in measurement technology with a focus on accuracy and methodology.
NotFivehead
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Homework Statement
Measurement technology problems
Relevant Equations
There is no single solution because there are multiple problems
1) Describe the Wheatstone bridge circuit and its condition for balance

2) What is shown in the figure? Explain its operating principle. Derive the relationship between the mechanical and electrical parameters.
(Strain gauge belongs to task 2)

3) We are measuring three-phase power using the Aron connection (2-wattmeter method). The power meter specifications are: I(n) = 3 A, U(n) = 300 V, cosφ(n) = 1, scale range = 150°, α₁ = 60°, α₂ = 72°, p(0) = 0,2.
a) What is the application condition for this connection method?
b) What is the active power consumption of the load?
c) What are the reactive and apparent power consumptions of the load?

4) We are measuring resistance using the V-A method. The voltmeter's measurement range is 50 V, and the ammeter's is 1,5 A. The measured voltage is 24 V, and the measured current is 0,8 A. The voltmeter's internal resistance is characterized by 2000 Ω/V, and the ammeter's internal resistance is 0,5 Ω. Both instruments have an accuracy class of 0,5.
a) Determine the measured value of the resistance!
b) Specify the circuit configuration that results in smaller systematic measurement error! Justify your choice! What causes this error?

5) We are measuring a DC voltage of U(measured) = 3 V using the following instruments:
- Deprez voltmeter, accuracy class h(accuracy class) = 0.5, measurement range U(measurement range) = 10 V
- Electrodynamic voltmeter, accuracy class h(accuracy class) = 1.5, measurement range U(measurement range) = 5 V
- 3½-digit digital voltmeter, error ±(0.2% FS + 2D), measurement range U(measurement range) = 20 V
Which instrument allows the most accurate measurement? Justify your choice with calculations!

6) The following waveform was observed on the oscilloscope screen:
a) What quantities can be measured based on the displayed waveform?
b) What is the phase difference between the two compared sinusoidal voltages?
(The picture with oscilloscope, belongs to task 6)

 

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NotFivehead said:
Homework Statement: Measurement technology problems
Relevant Equations: There is no single solution because there are multiple problems
Please post your best attempts at solving each of the 6 problems you listed.
 
renormalize said:
Please post your best attempts at solving each of the 6 problems you listed.
Sure sorry, I forgot to post, my bad!
 
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