Theory and Design for Mechanical Measurements
6th Edition
ISBN: 9781118881279
Author: Richard S. Figliola, Donald E. Beasley
Publisher: WILEY
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 5, Problem 5.5P
An automobile speedometer is graduated in 5-mph (8-kph) increments and has an accuracy stated as within ±4%. Estimate the design-stage uncertainty in indicated speed at 60 mph (90 kph).
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A Pitot tube measures a pressure difference Pa = Pt- Ps (dynamic = total - static)
between the front and side of the Pitot tube. The dynamic pressure is given by the
kinetic energy due to the airspeed v, allowing airspeed to be calculated from the
measured pressure difference.
(a)
P₁ = ² pv² ⇒ v=
When designing a Pitot tube, a manufacturer wants to make it precise enough to measure
airspeed to within 0.5 % uncertainty, i.e. = 0.005, at sea level.
Av
p=(1.225 +0.0005) kg/m³ at sea level.
(b)
2Pd
Av
Using error propagation, derive an expression for Simplify as much as
possible!
ΔΡΑ
Pd
Calculate the maximum permissible %-uncertainty in Pa, i.e.
allow the Pitot tube to meet the manufacturer's requirements.
Hint: Answer 1%
x 100, that will
The transducer specified in Table 1.1 is chosen to measurea nominal pressure of 500 cm H2O. The ambient temperature is expected to vary between 18 ∘C and 25 ∘C duringtests. Estimate the possible range (magnitude) of each listedelemental error affecting the measured pressure refering to the solution provided online,
Sensitivity error(eK)
= (±0.0025)(500 cm H2O)= ± 0.75 cm H2O
= ± 0.00375 V
how do you get 0.75?? shoud it not be 1.25?
according the answer, for sensitivity
What should be the surface tension of a liquid if its density, which is 1.44
g/cc, is the same as that of the calibrating liquid? The displacements of
the liquid and the calibrating liquid inside the capillary tube are both 0.5
cm. The surface tension of the calibrating liquid is 29.4509 dynes/cm.
Chapter 5 Solutions
Theory and Design for Mechanical Measurements
Ch. 5 - Prob. 5.1PCh. 5 - Explain what is meant by the terms “true value,"...Ch. 5 - SJ An official Olympics timekeeper once stated,...Ch. 5 - A tachometer has an analog display dial graduated...Ch. 5 - An automobile speedometer is graduated in 5-mph...Ch. 5 - An engineer reads the height of a mercury...Ch. 5 - Prob. 5.8PCh. 5 - Two resistors arc to be combined to form an...Ch. 5 - An equipment catalog boasts that a pressure...Ch. 5 - The shear modulus, G, of an alloy can be...
Ch. 5 - Heat transfer from a rod of diameter D immersed in...Ch. 5 - Estimate the design-stage uncertainty in...Ch. 5 - Explain the critical dift'erence(s) between a...Ch. 5 - A displacement transducer has the following...Ch. 5 - Prob. 5.18PCh. 5 - For a thin-walled pressure vessel of diameter D...Ch. 5 - Suppose a measured normal stress contains three...Ch. 5 - Prob. 5.31PCh. 5 - The area of a flat, rectangular parcel of land is...Ch. 5 - Estimate the random standard uncertainty in the...Ch. 5 - Estimate the uncertainty at 95% confidence in the...Ch. 5 - One use for a GPS rangefinder is on the golf...Ch. 5 - A pressure measuring system outputs a voltage that...Ch. 5 - The density of a metal composite is to be...Ch. 5 - A temperature measurement system is calibrated...Ch. 5 - The power usage of a strip heater is to be...Ch. 5 - The power usage of a DC strip heater can be...Ch. 5 - A thermocouple is a temperature sensor made of two...Ch. 5 - Time variations in a signal require that the...Ch. 5 - A hand-held infrared thermometer from a well-...Ch. 5 - The pressure in a large vessel is to be maintained...Ch. 5 - The cooling of a thermometer (c.g., Exs. 3.3 and...Ch. 5 - A J-type thermocouple monitors the temperature of...Ch. 5 - The density of air must be known to within 0.5%....Ch. 5 - In pneumatic conveying, solid particles such as...Ch. 5 - A step test is run to determine the time constant...Ch. 5 - The acceleration of a cart down a plane inclined...Ch. 5 - The heat flux in a reaction is estimated by Q =...Ch. 5 - A comparative test uses the relationship R =...Ch. 5 - A sensitive material is to be contained within a...Ch. 5 - A geometric stress concentration factor, K,, is...Ch. 5 - In Problem 5.9, we assumed that the errors in die...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- 3. Calculate a circular pressure tank volume and its uncertainty if the diameter, D, is 1.5 m and the length, L, is 3 m and the measurement are given with bilateral tolerance of±l cm. 2 2 ле si + Sy = tolerance in diameter tolerance in length where Sp= and Si = 3 3 D2 andV = ar²L=n-L 4arrow_forwardA temperature measurement system has the following specifications: -128 to 781°C Range Linearity error 0.29% FSO Hysteresis error 0.12% FSO Sensitivity error 0.04% FSO Zero drift 0.32% FSO FSO stands for "Full Scale Output". Estimate the overall instrument uncertainty for this system based on the available information. Use the maximum possible output range over the FSO in your computations.arrow_forward1. To determine the dynamic viscosity of a liquid you take repeated measurements of the liquid density and kinematic viscosity. These data are summarized in the following table: Avg. measurement Total Uncertainty P 999 kg/m³ ±0.5% V 1.23 mm²/s ±0.01 mm²/s kg Ns What is the dynamic viscosity? Give dynamic viscosity in units of; which is the same as ms 2. Determine the absolute and relative uncertainties in the dynamic viscosity.arrow_forward
- A transducer's certificate of calibration (excerpt below) identifies two instrument errors with uncertainties at 95% confidence over it range. Resolution Range Linearity error Hysteresis error 0.25 N 0 to 200 N Within 0.2 N over range Within 0.3 N over range 1. Estimate the instrument design-stage uncertainty. 2. What is the instrument standard uncertainty?arrow_forwardA temperature measurement system is composed of a sensor and a readout device. The readout device has a claimed accuracy of 0.6 °C with a resolution of 0.1 °C. The sensor has an off-the-shelf limit of error of 0.5 °C. Estimate a design-stage uncertainty in the temperature indicated by this combination. A displacement transducer has the following specifications: Linearity error:±0.25% reading Drift:±0.05%/°C reading Sensitivity error: ±0.25% reading Excitation: 10-25 V Output: dc 0-5Vdc Range: 0-5 cm The transducer output is to be indicated on a voltme- ter having a stated accuracy of 0:1% reading with a resolution of 10 μV. The system is to be used at room temperature, which can vary by 10 °C. Estimate an uncertainty in a nominal displacement of 2 cm at the design stage. Assume 95% confidence.arrow_forwardThe transducer specified in Table 1.1 is chosen to measurea nominal pressure of 500 cm H2O. The ambient temperature is expected to vary between 18 ∘C and 25 ∘C duringtests. Estimate the possible range (magnitude) of each listedelemental error affecting the measured pressure. How do I calculate the sensitivity error? The solution that was given: Sensitivity error(eK) = (±0.0025)(500 cm H2O)= ± 0.75 cm H2O = ± 0.00375 V My Question is, how do you obtain 0.75 since 0.0025 x 500 gives 1.25! please help. thanksarrow_forward
- The friction in flows through the pipe is defined by a dimensionless number called the fanning friction factor (f). The Fanning friction factor is represented by another dimensionless number, the Reynolds number (Re).It depends on the diameter of the pipe and some parameters related to the fluid. An equation that can predict f given the Reynolds number is given as follows. If Re =4000, e/D=0.01 in this equation, find the value of f using the Simple Iteration method by taking f0=0.1 as the initial value for the solution (ԑ=0.0001)arrow_forwardWe wish to measure a characteristic of a machined part whose nominal size is 50 mm at 20 °C. For this, two different instruments are used; an analog micrometer and a digital vernier caliper, both recently calibrated and with the same resolution (0.01 mm). The calibration certificate data of the analog micrometer and the digital vernier are shown in tables 5 and 6 respectively. In both cases the calibration uncertainty does not include the contribution of resolution uncertainty. Additionally, there are drift studies for both instruments and it is established that the drift of the micrometer is ± 0.002 mm while the drift of the vernier is ± 0.02 mm. The same number of measurements were performed with both instruments to avoid repeatability biases under controlled environmental conditions. Table 7 shows the results of the measurements of both instruments. The temperature of the piece was monitored with a digital thermometer whose calibration uncertainty is 0.1 °C, which already includes…arrow_forwardThe actual value of pressure differential for flow across a venturimeter is 60 mm WC. The measured values using a pressure sensor are; Confidence level 95% mm WC 59.8,59.2,59.7,60.2,60.3,60.1,60.5 Estimate Bias uncertainty (1) Precision uncertainty (2) Total uncertainty (3)arrow_forward
- The velocity of a falling parachutist can be computed by gm v (t) = (1 - e-(clm)) Use a first-order error analysis to estimate the error of vat t= 6 if g=9.81, m= 50 ± 2.5, and c= 12.5 ± 1.5. The error of vist[ m/s.arrow_forwardAs an instrumentation engineer you are asked to measure pressure with accuracy rate of±0.1%, what does it imply?If the pressure actual readings are 2, 4, 5 kg/m2in the full scale division of 10 kg/m2then whatare the possible measured values of pressure if accuracy rate of instrument is ±0.1% FSD ?State your answer with justification for the following whether it is accurate and precise,accurate not precise, precise but not accurate and not accurate and not precise.arrow_forward1| 2 | 3 | 4| 5 | 6 7 8 9 10 Measurement Flow Rate (liters/hr)| 1066 1022 | 1143 995 1004| 927 | 1024 | 945 979 | 1059 1. The table above contains 10 measurements taken of the volume flow rate through a pump running at a fixed operating conditions. Find the following statistical quantitie for this data set: a. The average flow rate: Vave liters/hr. b. The median flow rate: Vmedian liters/hr. c. The sample standard deviation: 0, liters/hr.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning
Principles of Heat Transfer (Activate Learning wi...
Mechanical Engineering
ISBN:9781305387102
Author:Kreith, Frank; Manglik, Raj M.
Publisher:Cengage Learning
8.01x - Lect 27 - Fluid Mechanics, Hydrostatics, Pascal's Principle, Atmosph. Pressure; Author: Lectures by Walter Lewin. They will make you ♥ Physics.;https://www.youtube.com/watch?v=O_HQklhIlwQ;License: Standard YouTube License, CC-BY
Dynamics of Fluid Flow - Introduction; Author: Tutorials Point (India) Ltd.;https://www.youtube.com/watch?v=djx9jlkYAt4;License: Standard Youtube License