Questions tagged [instrumentation]
The instrumentation tag has no usage guidance.
169
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Force Sensitive Resistor Calibration
I have been trying to calibrate FSR06CE Force Sensitive Resistor.
Data sheet here.
For starters I started by placing deadweights on the top of the FSR's active area and using a multimeter and DSO I ...
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Need Help Calibrating Force Sensing Resistor (FSR)
I'm currently working on a project that involves using a Force Sensing Resistor (FSR). However, I've run into a bit of a roadblock when it comes to calibrating the FSR. I don't have access to a weight ...
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3
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374
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How do I find the transfer function of a PID that uses a single op-amp?
How does one go about finding the transfer function of the following op-amp PID?
I have tried to convert each component of the circuit into it's transfer function representations, e.g., making each ...
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1
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97
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What happens during instrument calibration? [closed]
I've worked with a lot of instrumentation for both non-electrical phenomena (UV-vis spectrophotometer measuring DNA concentration, MEMS gyroscopes) and electrical ones (the usual oscilloscope, ...
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Differential probe shifting DC signal component
I was measuring the high side command and low side command of a synchronous buck converter when I saw the following phenomenom when I was increasing the input voltage of the buck. The phenomenom ...
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Resistance measurement: Agilent 34401A vs. Fluke 179
I was attempting to measure isolation resistance between the output of an isolated DC/DC converter to machine chassis. I was somewhat surprised to see a large difference in measurement between a 6 1/2 ...
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43
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Error in current measurement
I am measuring the error ratio and phase displacement in a CT. The experimental circuit is the next.
The results with the oscilloscope show that the error ratio is not within the limits of the class ...
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2
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1
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91
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Long Term Drift of IC
I wanted to calculate Long Term Drift of output voltage of an IC and in datasheet the value is given as 60 ppm/√kHr. I dont know what exactly this means as there is square root of kHr. Can anyone pls ...
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103
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Plain old SSH to Keysight DMMs?
I want to program some simple automation using test gear like Keysight DMM 34461A. I have done this sort of thing using VISA, SCPI etc (for example with pyVISA) over ethernet. But I'd like to know ...
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70
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How do 4-20 mA transducers work?
I am quite new to the instrumentation of electronics. I have noticed that most transducers that are used in the industry only use 2 pins, where it is usually marked with a positive 24V pin and an ...
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Wheatstone bridge analysis
Hello,
I am facing issues in calculating few parameters for the following information. I am new to this concept of strain gauge, wheatstone bridge, and data acquisition system
Four resistive strain ...
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87
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What are these PCB calibration standards?
I found these shunt resistors in a paper that uses them to calibrate AC equipment for EIS testing. They used the "frequency dependent complex impedance response" of these standards to ...
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245
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How to interpret the analog output of this humidity sensor?
I have been given a humidity sensor to work with and the only info I have is an AliExpress listing that says that it's based on the HR202L sensor.
The datasheet of the HR202L shows that its resistance ...
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52
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How to solve this calibration problem of National Instruments Elvis board?
I have NI Elvis II board and i am trying to calibrate my ELVIS II using the self calibrate option of MAX(measurement & automation explorer). I have tried my best to follow the instructions given ...
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217
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When calculating energy from a pulse measured with an oscilloscope, will the timestep always contribute a relative uncertainty of 1/2?
I am trying to calculate the energy delivered by a short electrical pulse. I am using an oscilloscope to capture the waveform and then exporting it to a CSV file. My scope took measurements at a rate ...
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Why does oscilloscope high-resolution mode for acquisition show inconsistent measurements?
Question: Why I get inconsistent measurements from scope specifically in high resolution mode,
i. At cold start higher values are obtained, as time passes measurements drift (gets lesser values)
ii. ...
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Why am I barely able to read the voltage changes with this circuit?
I'm using this EMG sensor to measure the EMG signal from my bicep. However, I can barely read the voltage change from an oscilloscope when my muscle contracts - the output is a horizontal line of 1.5V ...
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Does the needle of the galvanometer point in the direction the current is flowing?
Probably a little too simple for this site but I read different answers to this so I thought I would have the electricians weight in on this.
If this is true what law of electricity is it using to do ...
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Instrumentation Tools for Collecting Data in DRAM accesses
We can use instrumentation tools, such as Pin tool, to collect memory accesses of an application running on a system. The type (read or write) and memory address can be collected. How about data? Can ...
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650
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V-I Tester (aka ASA or Octopus or curve tracer)
I want to build a simple V-I tester and based on this article (or this) I did this easy circuit:
R1 = 560Ω
R2 = 100Ω
R3 = 1kΩ
where R1 and R2 is a voltage divider to set the \$V_{(DUT+V_{R_3})}=1VAC\$...
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I want to start by doing a circuit analysis of the triferential subtractor
I want to understand the circuit of the triferential subtractor:
in the context of Anderson loop based signal conditioning, found in this resource here.
This is just an inverting amplifier with a ...
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172
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Accuracy Class and Full Scale
I am using this formula to calculate the class of an instrument:
\$\text{Accuracy Class} = \frac{\max{\text{(Absolute Error in Range of Measurement)}}}{\text{Full Scale Value}}\$
The question is, FSV ...
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197
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How does temperature compensation work for pellistors in Wheatstone bridge?
Pellistors are used to detect combustible gases. Basically, the gas is burned inside the pellistor and the heat released will change the resistance of the detection element. The concentration of the ...
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212
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Current sense resistor vs transimpedance amp vs hall effect current sensor for instrumentation?
I'm using a photomultiplier tube; this creates a current output relative to the number of photons incident to it, on the magnitude of microamps. So, I need a precise and accurate way of measuring very ...
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What kind of protection does a circuit need to have for reading the output of a CT?
A CT (current transformer) is installed to measure the line current for digital measurement and protection devices. In many cases, the CT is installed in open weather or on poles, making it vulnerable ...
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242
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NTC thermistor circuit design - obtaining resistance values
I am trying to solve this circuit in order to compare to regular Op Amp thermistor circuits.
I'm using R4 as an NTC thermistor that ranges from 25ºC (6.24kOhm) to 40ºC (2.663kOhm), and VCC as 5V and i ...
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114
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How to determine electric field polarity from electric field mill signal?
I have built an electric field mill like this, more info can be found in the (short) wiki article:
It works by exposing the sensing electrode to the ambient electric field, which (depending on E ...
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4
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Averaging thermistor readings
I have 9 thermistors arranged in a grid, and I want to average the readings from these thermistors without code (that is, average them in a circuit rather than reading all the values into a ...
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Applications of coincidence detector
Will anyone tell me some of the applications coincidence detectors have in measurements and instrumentation? I would like to know whether there are any sensors utilizing coincident detection for ...
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Are data acquisition system and 'microcomputer on instrumentation design" and data logger the same thing? [closed]
This is data logger-:
This is data acquisition system-:
This is "micrcomputer on instrumentation design"
All 3 look quite similar. What is the difference between each of them? Sadly, ...
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What parameters dictates whether termination is required in this case?
After reading this question I was wondering about another scenario where the signal is not a square wave but a pulse train with short ON time.
As far as I understand, if we have a 3 MHz pulse train ...
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245
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Can I please get the data sheet for an IC in a blood pressure monitor, am trying to hack the data and send to cloud. JL Ic with number AC21CMDY9T-2B4 [closed]
This is the IC image, I need to hack the blood pressure monitor. The name of the model is KWL-W01
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378
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Purpose of soft iron in a permanent magnet moving coil instrument
Why is the coil in a permanent magnet moving coil (PMMC) instrument wound on a soft iron core, even though we are dealing with direct current?
Is it to avoid sudden increases in current, or because ...
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Why is the Wheatstone bridge configuration almost always used for sensors over a simple voltage divider? [duplicate]
Everywhere it seems to be taken for granted that a Wheatstone bridge is more precise, accurate etc. I don't see why it would be any better than a voltage divider if I am directly measuring the voltage ...
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280
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Understanding spectral resolution for a spectrometer
I am looking at this Hamamatsu mini-spectrometer, C12880MA.
The specs are,
Spectral response range: 340 to 850
Spectral resolution (FWHM) (typ.): 12 nm
Number of total pixels: 288 pixels
Now the ...
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Compensate Temperature with pressure sensor?
I'm using this pressure sensor and when I submerse the pipe inside the liquid the pressure should be held constant ,but due to the temperature the sensor keeps giving different values after certain ...
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524
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Parallel plate capacitor level sensor
Hey all.
in a typical design of a capacitive sensor for level measurements, compensation capacitors are added as a reference. I struggle to understand why we need a reference capacitance to measure ...
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How to design a data logger?
Signals from three transducers are to be recorded in data logger. The analogue signal supplied by the three transducers are dual polarity (-50 mV to +50 mV) having frequency is 5 kHz, 10 kHz and 15 ...
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201
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Multimeter as a variable load
I want to measure the current that can be supplied from a lead acid battery I have. (To know it's remaining current supplying capacity). To measure current I need to connect a load and an ammeter (...
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Measurement of delay between two signals using MSO4104 with PyVisa
I need to automate the measurement of delay between two signals using the oscilloscope. I am using MSO4104 from Tektronix. I programmed the oscilloscope for delay measurement, but I am not getting the ...
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Calculate the direct voltage common mode rejection ratio for an instrument in which a common mode voltage of 100V produces an error in reading of 5mV
Dv/dt = 5/100 =0.05V
V * 100 =0.05 * 100= 5V
This is what I did. I can't get it right. It's a measurement and instrumentation course, specifically an electronic engineering course.
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Referencing multiple differential pairs to ground before analog multiplexer
Yesterday I asked how to properly reference a differential signal (in my case from a current transformer) to ground, and got told that the impedance to ground should be matched at the location where ...
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Common mode noise rejection and grounding instrument current transformer
Suppose we have a signal from a current transformer over a pair of transmission lines. In order to prevent the voltage between the terminations of either of the transmission lines and ground from ...
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520
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Is there a commonly used name for a "local ground" or "local common"?
Suppose we have a circuit that measures some external voltage like so:
simulate this circuit – Schematic created using CircuitLab
We will assume that the circuit is powered by batteries, and ...
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Instrumentation amplifier first design [closed]
What are the steps to design an instrumentation amplifier using lm741 with gain=100 ?
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Can we control the data sending by Phasor Measurement Unit (PMU)?
Since PMU send the data after sampling the data to the PDC. Can we design any scheme so that PMU send the data to PDC only when I want? That means to reduced the communication bandwidth can we design ...
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differential instrumentation amplifier in LTspice not working
I was trying to simulate an instrumentaion amplifier in ltspice.
the problem i am having is the output when measured across C1 is wrong. since i have an amplification factor of 11, i was expecting to ...
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What is the maximum voltage I can set up on the AFG2125 function generator?
So, I'm picking up signals to work on the lab with the AFG2125 function generator. I have this generator on the lab https://www.gwinstek.com/en-global/products/downloadSeriesDownNew/5412/442 and on ...
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Standard SCPI Error codes?
I'm writing code that sends SCPI commands to various instruments (power supplies, o'scopes, data acquisition, etc.)
The TDK Lambda power supply is returning the code "C01" which means "...
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Potential issues with mounting tiny PCB directly to piezo transducer?
I am designing a very small signal conditioning daughterboard with the intent of mounting it directly underneath a cylindrical piezoelectric force device/"sensor" to rectify and filter the ...
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