Meter Definition and 304 Threads

Hi, I would like to know if anyone knows where can I find people who do certification of Sound Level Meter (Not calibration). I need to certify my Sound Level Meter to IEC 61672. Please provide details if you know who can do it. Thank you. Best Regards, Richard

Homework Statement i) The average concentration of 222Rn in air inside a building is 20Bqm-3; what is the average concentration of Rn in atoms per cubic meter? ii) In a sealed room of volume 50m3 what activity of 238U in a piece of porous rock would eventually give rise to this 222Rn...

i remember the French came up with metric meter by measuring the distance between equator and north pole and then divided by an integer to come up meter. it that still the defintion for meter? also, it seems now that a second is defined by the integer number of oscillation of atomic clock...

Homework Statement The tip of a meterstick rests on the can. The stick is pushed horizontally so that the can rolls on the table, with no slipping between the can and the table or the can or the can and the meterstick. The push continues until the can makes one complete rotation. During the...

I have been asked by someone about Smart Meters and this concern over radiation. I see several articles out there that warn of the risks, but few from reliable sources. When they talk about radiation they mean radio and microwave transmissions, which seems a bit scare tactic-ish. I'd like to...

Homework Statement I have a Coriolis mass flow meter and I'm supposed to run water through it at different flow rates. I have a motor / pump which is controlled by AC drive (which is controlled by potentiometer). Also, I have a pressure transducer mounted at the input side of Coriolis mass flow...

hello. i found a pdr-43 radiac meter at my local ham radio swapmeet today. the device looks like this: http://www.civildefensemuseum.com/southrad/im125dpdr43.html as a just for fun project, i would like to attempt to make it functional. right now the unit powers on but adjusting the check...

The circuit is below. This is from a quiz from earlier this semester. The equivalent circuit for the meter reduces to the D'Arsonval movement in parallel with a resistor who's value is R/2. I know that no matter what current you want to measure, R must be greater than or equal to 18Ω so that...

Hi, I am wondering if it is possible to "piggyback" off existing meters/indicators in a diesel generator? The generator has traditional analog 'VU' meters for voltage, current, and frequency. It also has standard analog gauge fuel meter, oil pressure, water temperature, rpm, and lamp/led...

You nose out a runner to win the 100 meter dash. If your total time was 11.8 seconds and you won by .001 seconds, by how many meters did you win? Help! Thanks!

If a analogue kWh meter is made of coil windings and coil windings dissipate harmonics currents then is it possible that we are being charged more kWh if we create harmonics on our circuit? I did a test once with a low power factor motor and 200 meters of extension cable. The power was coming...

I've been thinking about this simple problem a lot lately and it has been bugging me. Let's say you have a meter stick that weighs 100g and is 1x.001x.001 meters (so it's more like a rod). You probably don't need all that information but I'll include it to be safe. The meter stick is...

Homework Statement A meter stick, pointing in the x-direction moves along the x-axis with speed v=0.8c, with its midpoint passing through the origin at time t=0. A stationary observer situated at the origin takes a photograph of the stick at time t=0. At what poisition does the photograph show...

"The meter is the length of the path traveled by light in vacuum during a time interval of 1/299,792,458 of a second.Note that the effect of this definition is to fix the speed of light in vacuum at exactly 299,792,458 m/s." I don't understand this because how can you use a number based on...

Homework Statement The figure attached shows the meter used to study the motion yB = bsinωt. The motion of the mass relative to the frame is recorded on the drum. If l1= 360 mm, l2= 480 mm, l3= 600 mm, m = 0.9 kg, c = 1.4 Ns/m and ω = 10 rad/s, Determine the range of the spring...

Hi, I have a revision question, it's actually quite popular on the Internet but I would just like some help with it. A metre rule is supported on a knife-edge placed at the 40 cm graduation. It is found that the metre rule balances horizontally when a mass which has a weight of 0.45 N is...

Homework Statement A meter stick is suspended vertically at a pivot point 25 cm from the top end. It is rotated on the pivot until it is horizontal and then released from rest. What will be its maximum angular velocity (in radians/second)?Homework Equations I began by setting up a conservation...

If anyone could help, that would be amazing. its not homework, its a personal project i am undertaking and just wondered if anyone could give me an explanation or any help if they had any understanding of this circuit! thanks guys! Samm

I've been trying to determine how a power meter (like a utility company attaches to your house to determine your bill) works, but I can't find anything that explains exactly where the meter is taking it's readings. On a center tapped transformer, you have L1, L2, and Neutral, but the loads...

If i have let's say have 1 cubic meter of water at a temperature of 23 degree, in a closest system connected to a 1 cubic meter of air of 20 degree, how long time does it take for the heat to balance out, the surface between the two a 1 square meter.

I was reading that a meter is the length of the path traveled by light in a vacuum in 1⁄299,792,458 of a second. So the speed of light is exactly 299,792,458 m/s. I am wondering what is the uncertainty in our most accurate measurement of the speed of light. For example say I had a machine...

Homework Statement A galvanometer has a coil resistance of 460 Ohms and a full scale deflection current of 100 uA. What shunt resistance is needed to convert this galvanometer into an ammeter which has a full scale deflection current of 200 mA. What is the resistance of the ammeter when it is...

Homework Statement The Earth is surrounded by an electric field, pointing inward at every point. Assume a magnitude of E = 167N/C near the surface. What is the net charge on the Earth? How many excess electrons per square meter on the Earth's surface does this correspond to? Homework...

I didn't know where to post this question which is: What type of meter, which had very good loading characteristics, were used to measure voltages before digital meters were produced? I tried googling but it's all a jumble. can anyone guide me? thanks. Edit: is it a voltmeter?

Hi, I have forgo my previous idea of Tesla coil as my final year project and now moved on in doing an AC power meter monitoring, which monitors the kWh, voltage, current consumption of a device and remotely controlled switch to turn off/on the device.This power meter should be implemented like a...

]Hi Guys Can you help me with this : If a compressor with a displacement of 10 meter cube hour is displacing gas with a pressure of 10 bar, it is displacing 100 meter cube hour ?? (10 meter cube x 10 bar) rgds Marco

I'm using a capacitance meter that has 3 1/2 digits of display and lists the accuracy of its 200pf scale as follows: ±0.5% ±20 digit The ±0.5% is simple enough but I've not found something on how exactly to interpret +/- 20 digits of accuracy. I think it means as follows - can anyone...

of loose object in the center. This object is now surrounded by mass, will it hover exactly in the center of the hole, is there no gravity there ? If it is flexible, will it be expanded if it is expandable. How does one calculate this? (For realism, assume symetrical 2 meter channels from the...

Homework Statement A meter stick in frame S' makes an angle of 30° with the x' axis. If that frame moves parallel to the x-axis with speed 0.82c relative to frame S, what is the length of the stick as measured from S? Homework Equations Length contraction: L=Lo/γ The Attempt at a...

what is the best formula for elephants toothpaste not using yeast using potassium iodine and hydrogen-peroxide(30%) and of course soap. how much reactants would i need to fill let's say... 100m cubed (im not going to do that much but its easier to work with) * how long would the reaction take...

I'm looking for a way to measure force or impulse during collisions. I'm working on a project involving football helmets and collisions since it's in the news and was looking for suggestions regarding easily obtainable equipment I can possibly use to measure force or impulse during various...

Homework Statement A meter stick has constant thickness and width , but the material that the stick is constructed from is very strange ... it has a variable mass density that is given by, ρ(x) = 0.800(1 + 0.00250x) grams/cm3 where x is measured in cm. Find the center of mass of the meter...

I need a very accurate capacitance meter with capabilities down to + .01 puff. Any reccomendations?

A kid jumps a meter into the air. How long before he lands? The answer to this question is .95 seconds. I first calculated the time it took for the kid to fall downward. Which was about .45 seconds. But I used the acceleration of 9.8 m/s^2 since he was falling downward. My teachers answer...

Robert is jamming out on the air guitar and leaps a meter into the air on a hot riff. How long does it take before he lands? Thank you.

gas flow rate has units of "sccm" that standard cubic centimeter per minute. what does "standard" means here? how is derived? if there is gas flow of 1 sccm then how much gas flows in cubic meters?

Homework Statement i am trying to make an air flow meter using an heating element which i got from an iron..basically i have thought of inserting the element into a duct through which i will pass air using a blower,to connect the element with a 12v supply in series with a ammeter...thn i...

Homework Statement Meter in the circuit shown has a linear scale that has not been calibrated and the scale reading is 20 . When another resistor of resistance 2000 ohm is connected across XY . What is the scale reading of the meter Homework Equations The Attempt at a Solution...

Homework Statement [LIST] It was a standard venturi meter experiment where we calculated the theoretical and actual mass flow rates for different pressures and velocity's. the follow up questions were: -Compare the results of the coefficient of discharge obtained with typical values given...

Homework Statement A meter stick is hung at its center from a thin wire. It is twisted and oscillates with a period of 6.0 s. The meter stick is sawed off to a length of 70.0 cm. This piece is again balanced at its center and set in oscillation. Homework Equations T = 2PI / (omega) = 2PI *...

1. Suppose you are on the bank of a river at night. Opposite you on the other bank is a street light. You have a sensitive light meter and a meter stick. How wold you determine the distance across the river?

I often see website ads for home electricity meters that check on home power usage in order to help save costs by monitoring what is used so homeowners can adjust their usage to cut costs. However, is there a much more sophisticated meter available that oversees actual home usage and compares...

20 Liters per cubic meter of rain? A weather report for Chiclayo Peru said we received 20 liters per cubic meter of rain yesterday. How many inches of rain would a New York weather report say we received? Thanks. Tom

Suggest a reason why it is difficult to measure a large current (2000 amps) with a conventional meter in series in the circuit. The answer is: Even a very small resistance (in series) with 2000 A through it would generate much heat Why is this? How do we get this conclusion? From R=V/I...

Homework Statement The gauge pressure at the inlet of a horizontal venturi meter is 40kPa. The vacuum at the throat is 38 mm mercury. If a differential U-tube manometer containing mercury is the U-tube and the oil in the connecting tubes is connected to the venturi, what will the difference...

Standing on the top ledge of a 55 meter high building you throw a ball straight up with an initial speed of 29 m/s. How long, to the nearest second, does it take to hit the ground? If the building in the previous question was 56 meters high and you throw the ball at 30 m/s, how high to the...

Hey friends, I am trying to make a digital capacitance meter by using a HSC08 microcontroller chip (MC9S08QG8). Unfortunately this is one of those courses where one doesn't know anything because of lack of pre-requisites. Anyhow (enough complaining) what I have been trying to do is the...

What would be the effect on the results if the venturi meter was not horizontal and why? This is research i must complete before I carryout my experiment and lab report?? Help Plz

Dear all The eddy current dynamometers are used to load testing of motors and gearboxes.Can anybody explain the principle and operation of dynamometers and load testing accuracy.? Thanking u Prakash

Moment of Inertia A particle of mass 0.400 kg is attached to the 100-cm mark of a meter stick of mass 0.100 kg. The meter stick rotates on a horizontal, frictionless table with an angular speed of 4.00 rad/s. Calculate the angular momentum of the system when the stick is pivoted about an axis...