Questions tagged [measurement]

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

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1answer
152 views

Measuring distance at angle

I have a question, I want to measure a distance from an object of unknown shape and material, and I want to measure it under different angles, I want to measure a distance to just one specific point ...
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6answers
16k views

Measure weights with arduino

I want to measure weights with arduino. After the measurements, i want to analyze the weight data of the measured objects.Precision is not very important, but it should be work in the range of 10 to ...
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12answers
33k views

Ways to determine polarity (dc) without a meter

I came across this question about how to figure out the polarity of a cell phone charger without a meter. This made me think of what methods you could use to figure out the polarity other than using a ...
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2answers
363 views

RFI/AC Filter Rejection for Instrumenation Amplifiers

I'm attempting to measure the voltage developed across a very long piece of cable (upto 500m bundle). The issue is that the cable picks up a lot of noise from nearby radio stations and also has a 50 ...
3
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1answer
2k views

What is the effect of Saturation on a Ferrite Bead Inductor?

This circuit shows the "current channel" of an energy meter. IA_IN are the two inputs for a shunt (typically 250 uOhms) while TP1 is the connection to the energy measurement IC, which uses the 3.3 V ...
6
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1answer
130 views

Torque measurement device calibration

I don't know if I'm at the right place to ask this question but here is my trouble : I'm trying to find a good way of calibrating a electronic device used to measure small torques (0 -> 25 mNm). ...
19
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4answers
2k views

How can I measure the temperature wirelessly inside a piece of meat?

For a cooking experiment, I'd like to be able to measure the temperature inside a piece of meat while it's being cooked. Due to the mechanics of the cooking process, it's going to be difficult to use ...
6
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2answers
3k views

How to measure power consumed by mains device

I would like to measure the power consumed by a mains device. I have heard that it's not as trivial as simply measuring the average current, as the device may be resistive, capacitive or inductive, ...
6
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2answers
981 views

Will this ADC circuit work as intended?

Here is revision 6 of the circuit. Hows it look? :) (This is an ohmmeter circuit. It measures resistances from 1 to 10M ohm with an accuracy of 1%. The resistor (not shown) is measured between J5 and ...
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1answer
1k views

MCP 3909 energy metering chip problem

What I've:- I'm using MCP3909 energy metering chip , I'm setting this chip in pulse output mode which gives output pulses proportional to the real power . The used shunt resistor is 200 u Ohm . ...
6
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4answers
3k views

How to make single ended voltage measurements

I’m in the process of setting up a test rig to automatically measure and test induced PCB voltages. The device I’m using (we’ll call it the meter) makes single ended measurements. The PCB output ...
2
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1answer
248 views

Is it possible to build something that can measure water and oil in a tank with out being in the tank?

Say you have water and oil in tank....Is there any thing out there that can tell me how much water is in the tank and how much oil is in the tank???
2
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1answer
431 views

Tips about signal strength metering with percentage

I'm working with a device that receives digital television signals in the range of -40dBm to -100dBm. My tuner component has some status register that will give me a value for the signal strength, and ...
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2answers
5k views

Is this StopWatch Accuracy correct? [closed]

This question would be easy for anyone who has some tech experience with stopwatchs. I'm going to make some measurements. and I need a 1ms accuracy stopwatch. I found one that could do the work with ...
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3answers
703 views

A device that runs on AC current it's voltage inside is measured by always turning the multimeter's knob to AC voltage:same for DC right?

I've bought a cheap multimeter and it's not automatic. I've to manually rotate the knob. I live in North America. AC current is used in my home. Does this mean I can always measure voltage by turning ...
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2answers
1k views

how to detect variations of small resistances

I have a load cell whose resistance is varying between 318.0 and 318.8 Ohm. I have used a voltage divider but still the output voltage is rarely changing when the resistance changes. Is there any ...
11
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1answer
10k views

How does autoranging work in a multimeter? What is the circuit?

I was curious how this is done. It seems you would have to vary the voltage and current to measure resistance from 1ohm to 10Mohm.
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4answers
683 views

Common Analog Signal Frequencies

I'm trying to scope out what frequencies different common analog signals are. The DPScope design specs provides a list of common lower (sub 1 MHz) frequencies (copied below). audio (20 kHz) infrared ...
3
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1answer
6k views

How to hack a body scale to be used as digital weight measure

I am looking for help with hacking a typical digital (body) weighing scale to use in a custom application. Is there some internal digital or analog output in body scales to directly get the measured ...
3
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2answers
2k views

MCP3909 Energy metering IC , How to use the HFOUT in it?

I'm using the Microchip MCP3909 Energy metering IC, How to use the HFOUT in it ? note: HFout supplies a frequency output proportional to the average active real power . This frequency should be ...
3
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2answers
370 views

What are common control strategies for dosing pumps?

Dosing pumps means pumps that dose a specific amount with a high accuracy. In many process control scenarios, level gauges or flow meters are used (with low accuracy, at least in some cases), what ...
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4answers
3k views

How to mesure distance between two objects?

I have some idea about make something and make some small production. Idea is to have something that measure distance between two objects. First one called A size doesn't matter, can be connected to ...
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1answer
316 views

Measuring capacitance by using two thresholds

I want to measure capacitance using a microcontroller. As there are various drawbacks in measuring capacitor voltage from 0V, this resource has it right by counting the time capacitor charges from one ...
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5answers
4k views

Predicting thermal equilibrium: what's wrong with my time constant?

I understand that this is arguably a peripheral electronics problem, but it seemed to fit here better than in physics. I've been doing some power electronics design work with large IGBTs mounted on ...
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1answer
835 views

How to determine whether electrial appliance is On or Off using ADC or Optocoupler

I want to sense the On/Off state of an electrical appliance (e.g. light bulb 100W) using a microcontroller ATmega16L. How do i go about doing this? My mains supply specs are 230V, 50Hz
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2answers
903 views

Measuring power/current

I was wondering if someone knew how to measure power/current and then interface it to a micro controller to store the data onto some external memory. I basically want to measure the power a device ...
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3answers
6k views

How do electrical body fat detector work?

I would like to build me own electrical body fact calculator from a microcontroller (the Arduino), but I would like to know how does it work. I have a 5V analog reader, So I guess I sould calculate ...
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3answers
1k views

Is it possible to calculate effective value of a signal from its average value?

I have a signal which I want to calculate its effective value. The signal is a voltage value read on a 33.3m\$ \Omega \$ resistor connected series to a 220V AC power line. My aim is to calculate the ...
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2answers
380 views

Performance Analysis of PLC Modem

I'm an electronics and communications engineering student undertaking a project regarding the occurrence of Electromagnetic Interference (EMI) in power line communications (PLC). I would like to ...
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1answer
615 views

Schneider EGX100 Gateway with AB PLC 5 series [closed]

I was investigating hooking up Modbus devices to an AllenBradley PLC 5/40E using a Schneider Electric EGX100 Ethernet gateway. I can access the web server on the gateway device and monitor the slave ...
0
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1answer
291 views

Measuring rotation over z-axis (gravity axis) inside an metallic duct

Well from my first research from the web I wasn't able to tell if what I need can be done. The thing is, I need to measure the rotation over z-axis (yaw), in other words, to know the relative angle ...
2
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2answers
856 views

How do I use directional couplers on a differential signal?

I understand how a directional coupler can be used to measure signals travelling in one direction on a wire. What I don't understand is exactly how this would work on a differential signal, E.G. LVDS (...
3
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2answers
584 views

How to measure, with timestamps, changes in the received luminance?

I'm working on a project that is in need of some testings to validate it. I need to make some readings of luminance from a light source and store this reading with a timestamp (milliseconds precision)....
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1answer
146 views

I need help with project ideas that include the construction of an AD converter and…?

Disclaimer: Somewhat homework related. I apologize if this question is not challenging enough or not considered productive, but I need some direction for my final lab project. My partner and I decided ...
3
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1answer
2k views

How can I tell if something's controlled by an analog or digital input?

Is there a way to tell if something's being control by an analog or digital input without knowing and understanding all the rest of the circuitry involved? I have a Wowwee robot (Elvis) that I'm ...
4
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4answers
1k views

Cleanest method for measuring the reported speed of multiple computer fans?

This question builds upon this previous one How to interpret output of 3-pin computer fan speed sensor? which was asking about the 'sense' wire output from computer fans. I am designing a fan ...
3
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2answers
2k views

Sensors to detect and measure movement

I would like to know which sensors should I use in order to get measurement of a movement of my device (slow speed movement on a 2D plane, in cm or mm if possible). The goal is to find out if the user ...
4
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3answers
4k views

How to measure propagation velocity through a trace on a pcb?

With a pcb in hand, how to measure the propagation velocity of a path from point A to point B, with accuracy in the picoseconds range?
5
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3answers
306 views

How are new 'best performance in the world' devices measured?

Say you build an ADC or a DAC (or a scope/spectrum analyser) that has the best performance in the world. With what exactly do you test it with? I'm guessing: Build the best ADC. You'll get digital ...
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1answer
977 views

Weight measurement using load cell and process indicator

I need to measure 0-200kg using a Baumer SAS PA418 process indicator. The manual is in french, I tried to use google translate but understand very little. A load cell is attached with the indicator ...
4
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1answer
3k views

How to measure Li-Po battery leakage?

I'm working on a low-low power system, which is powered by a little solar panel and a Li-Po (Lithium-ion Polymer) battery, which can be \$20\$ or \$ 50\:\mathrm{ mAh}\$. The capacity by now is not ...
4
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1answer
302 views

How can I measure which finger is moving in a glove?

I am considering building a pair of gloves that make a chorded keyboard. In order to measure whether or not a finger should be triggered, I intend to leverage the fact that as you curl your fingers ...
3
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5answers
3k views

How can I measure small scale movement with an electronic component?

I'm working on a project which involves measuring the distance between two pins which are nominally 3-5 cm apart. These pins can move up to 1cm in either direction. I need to take a measurement of ...
4
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2answers
3k views

Measuring accelerometer frequency with an oscilloscope

I've got a VTI CMA3000-D01 digital accelerometer and I'm controlling it via SPI from a Texas Instruments CC2540 chip using the embedded 8051 MCU. In the datasheet for the CMA3000, it mentions that ...
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6answers
3k views

Measuring frequency of a signal above 5V with a microcontroller

I want to measure the frequency (up to 300 Hz) of a rectangle signal, that varies between 0V and Vtop, where Vtop is anything between 5V and 15V. Because I cannot apply more than 5V to the ...
4
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1answer
6k views

Measuring real and apparent power

I hope my question is in accordance with the rules of the site. I'm doing a power meter using a voltage transformer, a current transformer and an arduino, besides the components to create the ...
3
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1answer
5k views

Probing ethernet cables with a scope

I'm in the middle of a project that requires writing software that would send some packets over Ethernet every N milliseconds. The ethernet wire would go from a computer to a switch, and then to the ...
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5answers
2k views

Determine efficiency of converter

I would like to determine as accurately as possible (ideally within an error limit of +/- 0.25% or better, but I guess that's nigh impossible) the efficiency of a converter, using a simple method. I ...
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2answers
1k views

How do I measure impedance of my guitar pickups?

How would I measure impedance of my guitar pickups with a multimeter? Is it similar to measuring resistance?
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2answers
150 views

Client server WiFi structure

We have 3 measurement system and a master computer. Only the master computer have access to the Ethernet because of this we would like to use WiFi connection, but for this purpose I have no idea which ...