Measuring Definition and 1000 Threads

Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events. The scope and application of measurement are dependent on the context and discipline. In natural sciences and engineering, measurements do not apply to nominal properties of objects or events, which is consistent with the guidelines of the International vocabulary of metrology published by the International Bureau of Weights and Measures. However, in other fields such as statistics as well as the social and behavioural sciences, measurements can have multiple levels, which would include nominal, ordinal, interval and ratio scales.Measurement is a cornerstone of trade, science, technology and quantitative research in many disciplines. Historically, many measurement systems existed for the varied fields of human existence to facilitate comparisons in these fields. Often these were achieved by local agreements between trading partners or collaborators. Since the 18th century, developments progressed towards unifying, widely accepted standards that resulted in the modern International System of Units (SI). This system reduces all physical measurements to a mathematical combination of seven base units. The science of measurement is pursued in the field of metrology.

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  1. M

    Measuring the velocity of cosmic ray muons

    Homework Statement I'm participating in a worldwide undergraduate-level experiment to measure cosmic ray muons. I've got the data, and am in the process of writing a paper (called a poster for some reason), which details the experiment, procedure, and results. Right now I'm trying to...
  2. M

    Measuring metallurgical composition of melt in furnace

    When mixing special grades of alloys, or even in commercial production of common alloys, furnaces are often used where metals or additives are added and mixed, then samples taken at the core and characterized, then adjustments are made by adding additives until the desired composition is...
  3. T

    Measuring distance from an RF beacon

    Greetings, PF'ers I've got a project where I'm trying to measure the distance from a stationary AM radio beacon transmitting a short coded pulse every 300ms or so to a non-stationary receiver. I'm dealing with a range of about 1 to 500 ft between points. I need to have at least 1'' accuracy...
  4. B

    Measuring eccentricity of the ends of a shaft

    Hi! My name is Daniel and I'm new to this forum. I work as a mechanical engineer at a machining workshop in Norway. We are currently producing some steel shafts that require a high level of accuracy. The shafts are about 1500mm long, and has a diameter of 40mm h6 (+0,000mm, -0,011mm) all...
  5. S

    Measuring inductance with Anderson's bridge

    Homework Statement This is more to do with an experiment I'm failing terribly at rather than a direct homework question. I could not find the right section to ask this in. Investigate the inductance of inductors with cores of Perspex and Copper using an Anderson's bridge. For Perspex, compare...
  6. G

    Measuring non-ionizing radiation

    Does everything give off some sort of radiation? Example: water, oil, mud, etc. If so, how can it be measured? Is there a way to translate a radio wave into a frequency in the visible spectrum and see it bounce off a wall?
  7. P

    Measuring coefficient of friction of very light item

    I'm trying to measure the coefficient of friction between a wheel that weighs about 4 grams and a ping pong table. Are there accurate spring scales I can use to measure the force it takes to move the wheel? I'm estimate the force required to move the wheel to be in the thousands POUNDS (.00xlb)
  8. L

    Why is High Resistance Important for Voltage Measurement and Low for Current?

    Homework Statement Why would it be important to have the resistance high when measuring voltage and the resistance low when measuring current? Homework Equations The Attempt at a Solution
  9. J

    Weird results when measuring water evaporation

    I am doing a senior design project regarding water hydration and did some tests to get a general evaporation rate. I assumed that evaporation is proportional to the surface area of the water to air boundary so I thought that the water level of water in any constant cross section container should...
  10. M

    Measuring which path in Hardy's paradox, results

    I am reading a paper from Yakir Aharonov and others revisiting Hardy's paradox and I have a question. Let me state the notation first as brief as possible so that we can use it in the discussion: * a positron e+ goes through either the overlapping arm o+ or the non overlapping arm no+ of a...
  11. JJBladester

    Measuring velocity in a pitot-static tube and manometer

    Homework Statement A Pitot-static probe connected to a water manometer is used to measure the velocity of air. If the deflection (the vertical distance between the fluid levels in the two arms) is 7.3 cm, determine the air velocity. Take the density of air to be 1.25 kg/m3. Homework...
  12. F

    Measuring temperature of a current carrying conductor?

    how do i measure temperature of a current carrying conductor? i need to know the increase in temperature as i heat it up by passing a current through it. i read somewhere that i could use heat transfer convection equations to find it, but then i would need the precise value of the heat transfer...
  13. M

    Measuring water pressure differential in a pvc pipe

    I'm having problems with our pressure measurements on a pretty basic PVC water flow system. I drew up the general design in paint and attached it so you can have a visual of what I'm talking about. The second attachment is a picture of the actual pipe design. We're controlling the flow rate...
  14. B

    Measuring the density of an aircraft carrier

    An object floats if it is less dense than water. I'm assuming that an aircraft carrier can float because there are several rooms in it with air. What happens when the door on the upper most floor is opened? Does the air inside that room still contribute to the total average density of the...
  15. F

    Measuring Color Underwater: Techniques and Challenges

    Hello, I want to measure color of some objects underwater. I believe that one way of do that would be using the RGB system on photos. The other way would be measuring absorbance directly with an spectrometer, but I don't know how I can standardize my conditions. I have to measure the color of...
  16. S

    Measuring output voltage for rectifier with filter

    I need your help in understanding the concept. Actually, I am trying to understand the grounding concept here: Attached is the snapshot: Hi Folks, I need your help in understanding the concept of how to measure the output voltage. 1. Initially, I tried to monitor the voltage...
  17. J

    Measuring specific heat capacity

    I completed high school 9 years ago... please bare with me :) My problem is with how they calculate the actual answer - this is from an example problem in my textbook. Homework Statement A calorimeter cup is made from 0.15kg of Alu and contains 0.20 kg of water. Initially the water and...
  18. P

    Measuring Heat Transfer with a wattnode

    I am trying to measure the heat transfer from a sealant curing oven. My methods were to measure the surface temperatures of the inside and outside of the oven with 4 T-type thermocouples as well as the wattage supplied to the oven via a wattnode. The curing process is typically a 2 hour...
  19. T

    Physics Lab Experiment- Confused on what we are measuring

    In my physics class for an assessment we designed our own lab. In our lab we had plastic cups and cut small holes in the bottom ranging from 0.3 cm to 1.3 cm diameters. We then measured the amount of time it took for different volumes of water, detergent, syrup and rubbing alcohol. I...
  20. F

    Why Does My Doppler Effect Experiment Show Different Results from Theory?

    Homework Statement Hello, I did an experiment a couple of weeks ago to measure the doppler-effect. I have used a pendulum with a microphone attached to it. At one end i put a speaker which produces a sound with f =440 hz. T of the pendulum = 1,86 s. Vmax = 1,69 m/s. But if i try to measure T...
  21. J

    Need help calculating friction and normal force for Measuring Friction Lab

    Need help calculating friction and normal force for "Measuring Friction" Lab Hey guys, I'm not great at physics and have a lot of work ahead of me so I could use some help. The lab setup is a wooden block sliding on a wooden surface. There is a weight attached to the block by a string that's...
  22. C

    Measuring volatge across capacitor with a not ideal oscilloscope

    Homework Statement A resistor (R) and a capacitor are connected in series to an AC supply. You are measuring the voltage across the capacitor with an oscilloscope. however, the oscilloscope is not ideal. you may model the oscilloscope as an ideal voltmeter in parallel with an internal...
  23. H

    Measuring distance between objects of known size in photo

    Hi. I'm wondering if it's an acceptable method of measuring distance between two objects of known size by averaging their scales. In my case I have a photo of birds on the water. Each bird is known to be about 37cm long. I want to find the distance between two of them on the photo, the nearest...
  24. M

    Measuring Force on Class Project

    On my senior project, I've figured out everything I need to measure all the parameters I needed EXCEPT force. I know that I need to use strain gauges, and I've used them in my instruments class with Labview and a DAQ. While I'm still using Labview, I'm now using an Arduino so things are a little...
  25. sujoykroy

    Exploring Electron Spin: The Stern-Gerlach Experiment and its Implications

    Which experiment does show that electron has a spin of magnitude of \frac{1}{2}\hbar? I guess, Stern–Gerlach experiment shows that electron has a kind of intrinsic spin; because of which, particle beam gets deflected in some specific way under the application of an external magnetic field...
  26. lavalamp

    Measuring emissivity of material based on reflection

    Homework Statement I have a university project that involves comparing various paints with regards to how they affect the insulating properties of houses. As part of that I would like to measure the emissivity of the paint for a variety of wavelengths. Unfortunately I can not simply heat...
  27. M

    Measuring the Age of the Universe: Exploring Light & a Closed Universe

    How is the age of the universe measured? Is it by the distance light has traveled since the big bang? Does that imply a closed universe?
  28. C

    Adjusting and Measuring RPM On Lawn Mower Engine

    Hi, I have a lawn mower engine and I need to read and adjust its rpm precisely. I am totally lost. I would like to ask how some of you would approach this problem. What I have right now is I am going to buy an Arduino circuit board controller. Then I am going to attach a tachometer onto...
  29. J

    Measuring the White Noise Produced by a Resistor

    Hi all, I want to measure the white noise produced by a resistor in my circuit. In order to do this I did the following: 1. Ground the excitation voltage of the circuit and measure the white noise voltage produced by connecting the output of the circuit to a 8.5DVM 2. Subtract the Avg DC...
  30. S

    Wrong measuring of diode I-V curve in pulsed mode

    Hi. In order to measure the I-V curve of a normal diode in pulsed mode, I set up the following experimental kit. The experimental results do not change with pulsewidth, which is quite long (us regime), and low frequency (200hz and less). An HP pulse generator is connected via BNC cable to an...
  31. L

    Measuring curvature of space around a star

    I am wondering how space geographers would measure curvature of space around a large isolated star. i am thinking of the set up where there are two nearby spheres surrounding the star whose circumferences are already known. The remaining step is to measure the length of a radial geodesic segment...
  32. M

    Measuring Heat Loss in a Hollow Cylinder

    I am working on a problem where I am heating a hollow cylinder from the outside with a NiCr wire which is then insulated. The pipe is cooled by running water through the center of the hollow pipe. I would like to find the heat flux transfer rate outward. So my set up from the inside to the...
  33. B

    How Do You Calculate the Mass of Tritium in a Mass Spectrometer?

    Homework Statement An isotope of hydrogen passes, without deflection, through a velocity selector that has an electric field of 2.40 × 10^5 N/C and a magnetic field of 0.400 T. It then enters a mass spectrometer that has an applied magnetic field of 0.494 T and consequently describes a...
  34. B

    Measuring the speed of the moon

    I tried 5 times to get this problem, so I'm sort of heavily invested in it. Homework Statement How fast is the moon moving as it orbits Earth at a distance of 3.84 × 10^5 km?Homework Equations I'm using the kinematic equation: v = Δd/Δt Here distance will be 2∏r (I know that the moon's...
  35. R

    Why Choose Radians Over Degrees for Measuring Angles?

    What are the advantages to using one system to measure an angle over another. For example why do we measure angular velocity in radians instead of degrees? Are there any intrinsic advantages to one unit over another? Thanks AL
  36. O

    Measuring Delay Time for Solenoids: A Solution for Accurate Time Measurement

    I have a solenoid that is controlled by a PLC. I want to know what the delay time is from the time the PLC sends the signal to engage the solenoid to the time the solenoid is fully engaged. The time will be very short (milliseconds), but I need to know what the delay time is to within 5ms...
  37. M

    Chemistry - measuring the ammount of oxygen i need to to make MgO

    i have done the maths based on an online conversion calculator that said 1 liter of air is equal to 0.001m^3 in volume. my chemistry teacher tells me that my maths is wrong but won't tell me how... here is what i wrote: Failing the above, a larger crucible would hold more oxygen and the...
  38. Y

    Measuring classical object to arbitrary precision

    This has been nagging me in the background of my mind for many years and I've decided to get it sorted. I note that I'm not sure if this should be in the classical or quantum forum. I have heard it mentioned by many and often when referring to the inherent uncertainty when measuring...
  39. V

    Measuring a Rod in a Running Train: Why?

    Can anyone tell me what will happen to a length og a rod if it is measured in a running train and why?
  40. K

    Measuring Impact Velocity with a Ballistic Pendulum Prototype

    some device or contraption to measure point impact velocity - ballistic pendulum ? i hope you guys and gals can point me in the right direction for a prototype i am working on. I am looking for a device that measures impact velocity. much like a ballistic pendulum only much sturdier than the...
  41. H

    Choosing the Right System: Assessing Env. Params & Measuring Cantilever Beam

    1). Would you always go through a selection criteria to help decide on the most appropriate one to use if you had no prior knowledge of the system? 2). Would the environmental parameters need to be assessed for any kind of system regardless of the conditions? 3) Would the dimensions of...
  42. B

    Measuring drag coefficient experimentally

    Hello, everyone! Any ideas how to measure drag or drag coefficient on a body of simple shape? We should conduct an experiment without use of sophisticated equipment. Thank you!
  43. S

    Measuring higher voltages than rated oscilloscope capacity?

    I have a cheap oscilloscope that is rated for 10V input. I want to measure the quality of the output of my power supply due to a belief the DC filtering circuit isn't working well and producing harmonics in the signal (ripples). The output voltage is at a higher voltage coming out of a...
  44. E

    Measuring Resistivity in a sample of A356

    I'm trying to measure the resistivity of a sample of A356 to back out the thermal conductivity. I do not have anything sensitive enough to measure the micro-ohm resistance (my sample is 0.5" x 0.25" x 3"). If I want to use an oscilloscope or multimeter to measure the voltage drop, I should...
  45. micromass

    Misunderstanding about measuring the spin of the electron

    Hello, I have been researching a bit of quantum physics, and I have encountered a conceptual problem. Basically, we have an electron whose spin is aligned along some axis, and we wish to measure the spin along the z-axis. So what we do, is that we put the electron between two magnets. This...
  46. H

    CERN's OPERA Experiment: Measuring Faster-Than-Light Speed

    I have been reading and I think I understand what they were doing in CERN (OPERA) when they measured a speed faster than light. But I am not sure so I would like to ask you if I understand this right. As I understand it they "shot" two microwaves. The first one went straight to a "goal" but...
  47. U

    Measuring orbital angular momentum

    Can anyone describe an experiment that would be used to measure orbital angular momentum?
  48. C

    Measuring g with a spring without knowing the mass

    I have taken the challenge to measure the Earth's gravitational force, g, without knowing the mass of an object. To do this, we took a spring and had it oscillate vertically and determined the period T. Here is my theoretical development: F = -kx x(t) = Acos(ωt+θ) where ω = √(k/m) of...
  49. W

    Measuring the Length of a Parabolic Path with Line Integral

    Hi experts what is line integral - for example if I can draw graph of parabola and i can calculate the area under the graph. But how can i measure the length of parabolic path.
  50. J

    Equation measuring heat with temperature change, time and specific heat

    hello, If I had a substance (k) and heated it from Temperature1 to Temperature2, for z seconds, is there any (simple) equation that would give me the temperature (x) of this substance at the end? (knowing, of course, the substance's specific heat(C)) I found that: Q(energy exchanged during...
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