Measurement is the assignment of numbers to objects or events. All measurements consist of three parts: magnitude, dimensions (units) and uncertainty.

learn more… | top users | synonyms

2
votes
2answers
61 views

Creating a large 18650 Array

I am looking for some help with wiring for a large battery array using 18650 lithium ion batteries. Ok so I am looking at going solar and lead-acid batteries are too low overall capacity and their ...
0
votes
3answers
130 views

Current decreases while reading

I'm a bit confused about reading current on a breadboard using a multimeter (I'm a complete beginner with electronics). I'm using a self-powered breadboard which should deliver 5V / 1A. Multimeter is ...
0
votes
2answers
41 views

Circuit for measuring static charge

I want a cheap tool for investigating the source of and solutions for static electric shocks (from a vehicle). This link shows a particularly attractive solution; just a FET, LED, resistor and ...
1
vote
1answer
63 views

How does one measure the power factor?

How does one measure the power factor? $$\text{power factor}\equiv\frac{\text{power}}{|V||I|}=\frac{R}{\sqrt{R^2+(1/\omega^2C^2)}}$$ for an RC circuit driven with \$V(t)=V_0\cos{(\omega t)}\$.
1
vote
1answer
33 views

Vector Network Analyzer - The effect of increasing the number of measurement points

Does increasing the number of measurment points make the measurement time longer? RBW value does change the time, but does sweep bother the time of taking a single sample? I'm looking for ...
0
votes
1answer
32 views

Partial load failure detection circuit

I'm working on the power supply of a temperature controller which sends about 5kW of power maximum (230VAC 50Hz) into 3 sets of 12 heaters (actually, 3kW + 1kW + 1kW). I'm at the stage where I need to ...
0
votes
1answer
36 views

What's the usage of storing recorded measurements of multimeter and soldering iron station in computer?

Assume you want to purchase a multimeter for your job. some multimeters have a USB interface to store the recorded measurements in the computer and for this feature, you have to pay more money. but ...
0
votes
0answers
20 views

RIN measurement of CW laser

Right now Im doing an RIN measurement of a CW Raman fiber laser. In theory, Im supposed to see a relaxation oscillation which manifests as a single peak in the trace. What if I can't detect the ...
0
votes
2answers
37 views

Is Induction Wattmeter ,Energy Meter and Watt Hour Meter the same thing

I have a topic to study regarding Energy Meters. In the Syllabus it says Energy Meter, in the textbook it says Induction Wattmeter and one online reference by IIT, says WattHour Meter/Induction Type ...
0
votes
0answers
22 views

Does higher clock speed equate to higher resolution of distance measurement using RF?

I am trying to create a simple measurement system using RF but have found only devices that have fairly large windows of accuracy (+/- 1ft is the best one I've found yet). If I want to measure the ...
0
votes
2answers
34 views

Coil and Core-What exactly this is?

Im learning about electrical measuring instruments(PMMC).In this textbook it is said that a rectangular coil is wound on a aluminium former.Inside which there is an iron core. My question is what ...
0
votes
3answers
47 views

Which low pass frequency filter to configure to measure/calculate DC-DC converter efficiency?

I am measuring the DC-DC converter active power (P in watts) efficiency of a TI (Webench) LM3150 PCB that converts 12 to 5VDC. In the answer of question Measuring precisely the efficiency of a power ...
5
votes
3answers
152 views

How do utilities calculate transmission lines impedance?

I'm an electrical engineering student getting into Transmission Circuit Analysis, and a question came out to me: How do utilities measure their transmission lines impedance? Do they use special ...
2
votes
1answer
94 views

How to correctly use a LC meter/bridge

I have a LC meter at hand that I'd like to use it to measure the inductance (dominated by L1) of a circuit branch like this : simulate this circuit – Schematic created using CircuitLab ...
0
votes
3answers
56 views

Thickness Measurement

I would like to measure the thickness of a stack of paper without touching it. The measuring device needs to show if one sheet is removed. I do not need to know the measurement in inches. Units are ...
1
vote
2answers
96 views

How can I make the dimensioning of a temperature monitoring circuit?

I need to design a circuit to measure temperatures in the range 15-40 degrees C (this will later be the basis for a regulator of a peltier-element for a fridge). I tried a circuit using the ...
3
votes
0answers
90 views

Under water distance measurement

For a laboratory / field test, I'm looking for an easy solution to measure the soil surface elevation. The test runs a flow on a bed. When the erosion takes place the sediment concentration goes high ...
0
votes
1answer
77 views

Characterization of Power Harvester

I have chosen a power harvester to power a few things as part of a wireless system. This one is the one I have and it seems to be operational: http://www.powercastco.com/PDF/P2110-datasheet.pdf ...
2
votes
4answers
397 views

Is this true RMS?

This question is about obtaining a true RMS voltage reading from a running sampling ADC. Does this give me a true RMS reading, or where did I made a mistake? Construct a ring buffer of an large ...
-1
votes
1answer
87 views

Measuring Output Amps From a Power Supply

I am in the quest to build a cheap bench power supply, i have successfully designed, built and tested the entire voltage circuitry. The device includes a graphic LCD screen that displays the voltage ...
0
votes
2answers
34 views

Technique to measure/infer Vf for LED given If

This isn't the normal resistor question, and I'm familiar with the theory and Which is better: using a resistor with an LED, or "precisely" matching the Vs to the given LED's Vf rating? ...
1
vote
1answer
79 views

How to measure the quality of a USB charging cable?

I have a set of USB cables (data and charge) and I noticed that, for a given charger, the charge time differs by cable. What would be a good way to measure the charging fitness of a USB cable? ...
1
vote
1answer
62 views

Abstract Datasheet Dimension Notation

I am attempting to create a footprint for a Surface Mount Component and I am using the manufacturer's datasheet for reference. They include PCB dimensions but the notation used is a bit confusing. It ...
0
votes
0answers
53 views

how work this flow meter

As you know , The principle of operation for the magnetic flow meter is based on the Faraday’s Law of Electromagnetic Induction.An electrical current (I) is applied to a coil package inside the flow ...
0
votes
0answers
41 views

How to calculate distance between two objects(robots)?

If I have two soccer robots, and want each robot knows the distance between itself and it's teammate, how can I do that? (without external supervisor camera)
0
votes
2answers
91 views

How to break out SMD chips in-circuit?

For a current project I am attempting to amplify and cross-wire the signals from the address pins of SMD RAM chips. Basically this means I am trying to break out the pins of a SMD chip, similar to how ...
0
votes
5answers
167 views

How measure the voltage over a large resistance?

I know initially this question might come across stupid and obvious but all is not as it seems. I want to measure the voltage drop over a 10M ohm resistor but my voltmeter's probes have an ...
0
votes
0answers
44 views

IR temperature Sensor reading ambient temperature in a room

I bought a product that has a IR temperature sensor and I want to receive a "good quality" ambient reading of a room. I have an idea how to use the IR sensor for the ambient, even though it would be ...
0
votes
3answers
154 views

How to measure nano-amps easily?

I want to measure the stand-by current of the PIC, but my DVM has minimum 2000micro (u) amper switch. It shows 0 micro amps when in 2000 u amps mode. Without building circuit a complex (more than 3-4 ...
0
votes
1answer
84 views

Anyone may suggest a temperature sensor technology that will work to a max of 200ºC?

Cheapest sensor technology as possible, up to +- 5ºC or 5% of accuracy. Better if it doesn't need complex (and costly) additional circuits.
0
votes
1answer
47 views

Uncertainity Calculation

> How can i calculate the absolute uncertainty dt in the following case T=(P/A)^1/4 if ...
1
vote
2answers
92 views

Big capacitors measurement(LCR meter related)

I digged up some capacitors from amplifier and decided to test them, one of them is said to be 8200 uF, the other 4700 uF. I measured them with LCR meter and it gives very strange numbers. If LCR ...
0
votes
2answers
100 views

Full wave AC Voltmeter Vs True Rms Voltmeter

Does a full-wave rectification AC Voltmeter give the same indication as a true rms voltmeter when you measure a 50 Hz sine wave?what happens if the the sine wave is clipped by an inadequate ...
1
vote
1answer
104 views

Is using a transformer at reduced voltage a bad idea?

My Google is failing me. I want to make an isolated AC voltmeter capable of working at 120 or 240 VAC. I've found a suitable 240 volt to 5 volt transformer to use (current capacity doesn't matter - ...
3
votes
1answer
77 views

Power supply noise measurements

Im working on a project where I need characterise the noise from a power supply so I can then design some filters. The power supply provides 5V, 12V and -12V to a set of analogue sensors (hence the ...
0
votes
2answers
147 views

Oscilloscope measuring of PMT in photon counting mode

I have a setup as drawn below: DC source of 15V connected to high voltage (HV) source of 1500V connected to photomultiplier tube Hamamatsu, R1-R3 are resistors builtin the socket of PMT (there are ...
3
votes
1answer
130 views

How can one measure extremely low-uf capacitors?

I'd like to measure (to a few percent precision) the capacitance of a 0.8-0.06pf variable capacitor (eventually to be read by a 120mhz 32-bit microcontroller, if that's any help). I realize that one ...
0
votes
1answer
151 views

Measuring inductance and ESR of a motor using LCR meter

I am building a circuit, where a MCU will drive an unipolar stepper motor through MOSFETs and constant current source (not included in the schematic). simulate this circuit – Schematic ...
1
vote
1answer
86 views

Would adding an LED to a multimeter's LCD screen affect readings?

I purchased a TekPower TP4000ZC multimeter, which has no backlight for the LCD. I wish to add one myself, perhaps a single led at low current, driven directly off of the two AA batteries. I'll add a ...
0
votes
1answer
81 views

Long term voltage change - analog voltmeter, op-amps and logarithmic scale

I want to display one minute voltage change on analog voltmeter. Voltage change: from -0.5V/min to +0.5V/min. My analog voltmeter has 0-10V scale (I will replace it with homemade printed scale). ...
2
votes
1answer
180 views

Why is the capacitance changing while measuring?

I have 2 different 100nF capacitors. Let's call them A and B. My dad told me that B is "better" than A. I've tried measuring their capacitance using a Metex multimeter which has the option of ...
2
votes
1answer
109 views

Transformer frequency dependence

I have a transformer that I've taken out of scrap. I'm trying to discern it's electrical specifications. In my setup I have a function generator hooked up to the primary winding, and an oscilloscope ...
0
votes
1answer
69 views

Multimeter capacitance

I am using Multimeter Voltcraft M-4650B to measure the voltage in the test point of a high voltage circuit. I want to find out the stray capacitance of my cable and for that I need to find the ...
0
votes
2answers
149 views

TTL signal: output impedance, overshoot and other characteristics

I have an assignment for my Electronic Measurements and Instrumentation course, specifically me and my group were asked to perform time and voltage measurements using reflectometry on coaxial cables. ...
1
vote
1answer
85 views

Measuring components of current

When measuring input current to a primary winding of a transformer with an inline true RMS multimeter, can no-load current be measured, then full load current be measured, and then simply subtract ...
3
votes
3answers
281 views

What is the test voltage of a ohmmeter?

Ohmmeters don't appear to make LEDs conduct which gives overestimates in the resistance measured (tested with a R1//(R2+LED) parallel circuit). So what is the voltage they apply to the circuit, ...
0
votes
1answer
93 views

How to measure power/energy with analog circuit?

I would like to measure either power (running average, for example exponential average with a certain time constant) or energy (power integrated over time) with an analog circuit. The setup I have ...
1
vote
2answers
122 views

Why are null measuring methods considered to be very precise?

I heard a professor saying "it's a null method, so it is very precise". He was talking about the force balance pressure measuring method. I think in this cathegory of methods one can include the ...
1
vote
0answers
25 views

Sony Ex Data Acquisition Frontend

I am looking for information on a third party driver for the Sony EX-IF10 data acquisition frontend. I know sony made drivers for Matlab and Labview as it was advertised in promotional materials. ...
2
votes
2answers
248 views

Why not use audio codec chip as measurement ADC/DAC?

I am working on a project that needs simultaneous ADC/DAC. The specs of the on-board ADC in typical microcontrollers are pretty weak, and separate ADC with good specs are much more expensive than ...