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# Questions tagged [measurement]

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

96 questions with no upvoted or accepted answers
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41 views

### Cortex-M DWT cycle counter inconsistent measurement

I recently discovered that it's possible to use a free running counter embedded in most Cortex-M4 cores to measure the performance of a chunk of code. I'm trying it on my LPC4370, where I want to ...
47 views

### What is a suitable hysteresis value and averaging period for a residential thermostat?

I've built a microcontroller based thermostat that I am using to control my home HVAC system. The actual programming and physical assembly has been straightforward. I'm using DS18B20 sensors, so I ...
57 views

### Measuring integrated current

I want to measure the amount of light striking a photodiode in a specific time window (about 1ms). In this window, we get $10^6-10^7$ photons, which get converted into electrons with about 80% ...
93 views

### How might the Lecroy HVFO High Voltage Fiber Optically Isolated Probes Work Internally?

I've been looking into these fiber isolated probes that Lecroy makes (http://teledynelecroy.com/probes/probeseries.aspx?mseries=537), and I'm curious how they're sending the signal over the optical ...
107 views

### How to properly store big values in parallel SRAM

For a project I need to determine the frequency and phase-shift of up to 16 channels. The frequency range is 0 to 3 kHz and the signalform is square. My first idea was to use the following circuit ...
820 views

### What is the accuracy of a thermocouple after calibration?

I'd like to use a thermocouple to create a general-purpose temperature probe. However, the accuracy is quite a bit lower than I want. Almost every source I look at (example) lists the accuracy of a ...
141 views

### Precision Tracking filter required

I don't mind if it's a band-pass or low pass filter (although I think low-pass will give a better result). Input operating frequency range is 100Hz to 1kHz. Input amplitude will be about 1Vp-p and ...
65 views

### How dual gyroscopes can be used to remove gyro drift?

I need to measure yaw/heading/azimuth correctly. Now, I have done with gyro with very strong filtering and the results are very low yaw drift and even when there is perfect calibration then there is ...
30 views

### How do I measure the fluctuation of a pulsed voltage of ~1700V?

The problem: See the little sketch. Starting from a high-precision DC power supply, I pass the voltage to low-pass filter and a pulser. This pulser pulses the nominal voltage of around ~1700V down to ...
102 views

### Measuring wow and flutter of a phonographic turntable with digital equipment

Old school way to measure: 3000 or 3150 Khz test tone from test record played back through phono cartridge/preamp into wow/flutter/drift meter and for turntable that has an electronic adjustment to ...
41 views

### What is the difference between residual phase noise and absolute phase noise?

Studying the characteristics of an oscillator with a phase noise analyzer, but I don't quite understand the difference between absolute and residual noise. Any help would be greatly appreciated
125 views

### Wrong measurement of DSO-5200A?

I'm using a DSO-5200A from Voltcraft and noticed the voltage measurement represented incorrectly (it is doubled). Any ideas how to reset this? Channel 1 (green) measures a (noisy) 5V and has a Vmean ...
63 views

### Amplifying pulse signals causing pulse lengthening problems

I am currently trying to design a circuit that would sense a voltage change at its input, convert that change into rapid "on"/"off" change at output and amplify same switching voltage to high current (...
87 views

### How can I make my measurements of full-wave rectified AC using an A/D match a Fluke meter on its DC range?

I am trying to measure the DC voltage of a full-wave rectified 60Hz AC signal using an A/D and have it match what a Fluke meter reads on its DC scale. My current approach is to take as many (16 bit) ...
71 views

### MEMS Microphone noise floor power level & audio noise spikes measurement

I have a circuit with a MEMS microphone and would like to be able to measure the audio noise spike contents and check the noise floor power level in the audio circuit. My intention is to connect the ...
109 views

### Power consumption measurement on the bench

I've been using the Atmel Power Debugger to sort out power consumption issues on some µController based circuits... and have been pretty pleased. Unfortunately, it's limited to a maximum of 5.5 volts ...
49 views

### Measuring resistance of switched load

I am in the process of designing a custom vaporizer. So the main coil with a resistance ranging from 0.2 Ω to 2 Ω is switched using a MOSFET shown in the circuit diagram below. ...
51 views

### Using a scope for an instrumentation and mains earth

When I make a measurement using a scope and observe transducer voltage output on the scope screen, I want to eliminate the noise as much as possible which is due to device and scope coupling or common ...
173 views

### What's inside a reed switch that cannot be tested with a multimeter?

I'm shopping for reed contacts that are rated for 230V AC, because I don't want to use an always-on power supply just for a relay and a reed switch. This is surprisingly difficult, but I found this ...
255 views

### Measure input capacitance of I/O pin

I'm looking for a simple laboratory procedure (and required equipment) to measure the input capacitance of each IC I/O pin. Thanks in advance.
99 views

### Period Measurement

I am reading a book about the measurement in communications. There are a lot of information about how to measure frequency and period of signals. OK, i have understood that we should measure the ...
83 views

### How to figure the wiring of a 4 cable pc fan without frying it?

I have a 2 spare PC Fans which come with a four cable wiring and I would like to reuse them as ordinary fans (running at full speed all the time) outside a PC box, powered by a 12v source. ...
1k views

### Calculating AC Input Power

I'm making an AC to DC power supply that connects to mains. There's an AC to DC converter, buck converter and a smoothing LDO that outputs a DC controlled with pots. I'm verifying the supply, and ...
89 views

### Am I right about measuring current, and power

I have a meter that can measure: current, active power, reactive power and complex power. simulate this circuit – Schematic created using CircuitLab So, when I measure the four things: current,...
449 views

### Measure output AC voltage and current from a DC/AC inverter

As the title, I'm trying to measure and display 230VAC voltage and current from a DC/AC inverter on an oscilloscope. I don't know if I can proceed to measure them directly with these equipment: -...
86 views

### Why do we need voltage stabilizion in bridge measuring system with ratiometric connection?

i found in many weight scale reference designs that they use either low noise linear regulator or voltage reference for voltage stabilization. Why do we use them if ratiometric design cancel the ...
57 views

39 views

### Contribution of solder parasitic to S parameter measurement

I have an antenna. I want to measure S-parameters of it using a network analyzer. The antenna has to be soldered to SMA cable for the measurement of S-parameters. After the calibration, will the ...
28 views

### How can I safely measure the output power of an RFID reader?

I want to measure the output power of a UHF RFID reader. I connected the antenna cable to one of the antenna ports of the RFID reader and to a spectrum analyzer (Hewlett Packard 8568B). There is a 10 ...
47 views

### Is it possible to measure impact force using Flexible PVDF Piezoelectric Film?

If it is possible , should i use integrator circuit first to hold the signal then follow it by other signal processing signals (amplification and noise filtering ) ? , knowing that i tried to connect ...
74 views

### How can I measure the actual magnetic strength of my electromagnet to compare against my calculations?

I am interested in building small scale electromagnets and I wanted to measure their actual magnetic strengths to compare against my calculations. What are possible ways to measure the difference?