Measurment Definition and 22 Threads

Hello, I have made a capacitive water level sensor. It is a parallel plate capacitor. While measuring the capacitance of my sensor, I measure 53 pF. I then leave it for couple of minutes, still conected to the meter, capacitance then rises to 54 pF. Capacitance is slowly increasing. Why is...

I was studying ECG measurements and come across the frequency of ECG. I couldn't find for sure the frequency of what this is? Is it the frequency of sampling(times of measurement) or is it something else?

I am trying to both design a code for Arduino and build a circuit connected with the Arduino which uses 3 anode 7 segment and 3 resistor arrays with 7 pins to connect to the Arduino Uno. The encoder is a rotary encoder. I have Pin A of the rotary encoder connected to pin 13 of the Arduino and...

Homework Statement I am having a issue conceptualising the problem as I believe the answer is 0. Part c) Homework EquationsThe Attempt at a Solution My answer is 0 and it for the following reason. A the being say time t=0 the system is in some arbitary state, then when I got to measure the...

Any pure state of spin-1/2 particle can be represented by a superposition of spin up and spin-down relative to an arbitrarily direction. lw>=a l+> + b l-> where a^2+b^2=1 If there is no magnetic field, the measurement of the spin is random and we get 50-50 chance to be spin up and spin down...

Hi, I want to know about viscocity sensor working principle to find the level of grease available in a gear system? Any inputs ?

Is there a way to estimate the upper limit and lower limit of time for doing a work? Suppose we are learning a page of facts and want to estimate the upper and lower limit of time taken to do so. If we start estimating the time we will find that the pages are learned in some variable periods of...

I have a concern about having some wave function psi, that is originally a superposition of many eigenstates (energies). Traditionally, it is said that the square of the coefficient of each of the component eigenfunctions represents the probability of measuring this particular energy eigenstate...

Hi. If we place two perpendicularly oriented linear polarizers at a double slit, there will be no interference pattern. In the wave picture, this is trivial: Two waves with perpendicular polarization cannot interfere. In a quantum picture, I've often seen the interpretation that the sheer...

what is the best quality to know if a gas for example became solid ...soldification Speacking about small quantity of gas that we can't see with our eyes ... what electrical quantity that i need to read to know that this very light gas become a solid metal and could that quantity give me...

I wanted to study electrical behavior of thin films. Can anybody suggest me suitable source measure unit please? (also of low budget) Power supply: Voltage (few volts) measurement: current (micro- milliamps)

Hello, I have been working on a personal project involving the transfer of liquid CO2. I want to figure out a way to measure the transfer of liquid CO2 from one cylinder (supply cylinder) to another (receiving cylinder) and get an exact measurement of how much CO2 was transferred into the...

How can i make electrical measurment of Oxide. I know i have make an ohmic contact to use that as an electrode. But how do i decide the metal for this contact. I want to use Ga2O3 Thanks in advance

Hi Reading another post about the inverse square law by trewsx7 on this forum, I had the idea that maybe the gravity field isn't constant at some parts. Imaging a 2-dimensional gravity field produced by a source. Considering ∏, there might be a repeating infinitesimal patterns on ∏ where...

hello I have a question: i am trying to understand how we find out that the curvature of the universe is zero using the angular size of the hot spots of the d microwave background radiation. http://scienceblogs.com/startswithab...tire-universe/ there is a picture in this blog showing the...

In the books I've read about relativity the introduction is a definition of simultaneity which is given by the famous train and track example.I've thought a lot about it and concluded that the difference is just in the measurment.I mean the man on train thinks thunders are not simultanous and...

I have some questions: Was it von Neuman that first brought up the idea that self-reference could be the reason behind the measurment problem? The idea seems to be that since a measurment device can't measure all possible interactions between a particle an itself the system (device and...

Hi, I did an experiment where one of the 'questions' was to determine the self-inductance of an inductor. I am going to leave out the experimental method, but if you need to know just say so and I'll try to explain. The value I got was L = (3.910 \pm 0.009) \text{ mH}. I am fairly confident...

I'm trying to find out some information on the piv system and how it compares to other systems of measurement. Essentially I want to know if anyone knws any disadvantages of the piv (Particle image velocimetry) system. Thanks Transformer

I have 2 horn antennas facing each other each has a size A & B respectively they operate at a frequency 800MHz to 2.5 GHz. they are a distance D apart. when making gain measurments there is a ringing effect which changes as the horns are moved futher or closer apart. Does anyone know if this...

Hi, I don't know whether the conserved quantities in QM are conserved in every conditions. For example, a state can be a non-eigenstate of energy, and when we measure the energy of this state, it falls into an eigenstate of energy. The former state does not have a definite energy, but the...

Hello. I know that the United States officially uses the Imperial Measurement System (eg. feet, inches) instead of the Metric System (eg. centimeters, kilometers). What system is most commonly used at universities in the US? Are courses in the US taught primarily in the Imperial System...