# Questions tagged [instrumentation]

The tag has no usage guidance.

151 questions
Filter by
Sorted by
Tagged with
59 views

### 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 ...
103 views

### 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 $V_{(DUT+V_{R_3})}=1VAC$...
• 1,616
52 views

### 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 ...
• 51
55 views

### 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 ...
79 views

### 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 ...
52 views

### 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 ...
• 109
73 views

### 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 ...
• 2,041
1 vote
61 views

### 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 ...
58 views

### 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 ...
• 545
669 views

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 ...
71 views

### 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 ...
43 views

### 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, ...
53 views

### 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 ...
• 1,303
108 views

### 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
• 11
134 views

### 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 ...
• 1,124
92 views

### 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 ...
1 vote
106 views

### 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 ...
• 11
42 views

### 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 ...
1 vote
196 views

### 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 ...
• 11
87 views

### 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 ...
• 27
92 views

### 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 (...
114 views

### 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 ...
• 572
50 views

### 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.
• 1
68 views

### 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 ...
• 287
119 views

### 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 ...
• 287
231 views

### 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 ...
• 13.1k
49 views

### Instrumentation amplifier first design [closed]

What are the steps to design an instrumentation amplifier using lm741 with gain=100 ?
22 views

### 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 ...
• 61
1 vote
290 views

### 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 ...
• 13
96 views

### 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 ...
• 1,117
1 vote
412 views

### 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 "...
132 views

### 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 ...
• 181
55 views

### What is RF switch used for in a lab equipment? [closed]

I'm only familiar with scopes, DMMs and a little spectrum analyzers. But I couldn't understand what an "RF switch" is used for particularly in a characterization lab. Can you give an example of its ...
• 1,117
416 views

### 4 - 20 mA current loop, short circuit isolator

I am trying to design a short circuit isolator, for 4 - 20 mA current loop based intruder alarm system. The below system, identify short circuit in sensing line and sensor activation (closing 1 k in ...
• 17
1 vote
55 views

### How are in practice input output impedance measured of a prototype circuit?

When an analogue circuit like an audio IC or an ADC for instance is implemented, is there a dedicated instrument/device which measure the input output impedance of the circuit or one has to perform ...
• 1,117
319 views

I have a 1kN force transducer which can output (through an amplifier) +/-10V for +/-1kN nominal force range and I sample it with a DAQ device which is 24-bit and has +/-10V range. The overall noise ...
• 1,117
138 views

### Gain-Phase measurement without dedicated equipment

I was wondering if it is possible to make Gain-Phase measurements without dedicated equipment like the venerable HP4194A or a more modern Bode 100. As far as I understand, a Gain-Phase analyser is a ...
• 939
1 vote
51 views

### How to do multichannel ADC data logging

I need to build a system to monitor several (around ~20) voltages over several days. The ~20 voltages need to be measured differentially. Something which could in theory be accomplishes with 3 of ...
• 939
37 views

### Inamp to Measure LiFePO4 Battery Voltage

I know there are a few posts regarding the best way to measure battery voltage but I didn't see any that were focused on the most precise method possible. I am designing a battery analyzer to measure ...
• 11
50 views

### Is there some kind of standard of modbus input register?

As the title said, based on your experience, is there a such thing? If no, which are the most commonly used? for example in a sensor, the input registers as follows: ...
22 views

### Error Propagation and Analysis on a experiment due to Voltmeter Constraints

I got a situation: at the moment I am unable to access both channels for Keithley 2182A nanovoltmeter using LabVIEW. However, for some odd reason, while I cannot access the channels at once, LabVIEW ...
61 views

### Error Analysis due to Voltmeter Constraints

I got a situation: at the moment I am unable to access both channels for Keithley 2182A nanovoltmeter using LabVIEW. However, for some odd reason, while I cannot access the channels at once, LabVIEW ...
1 vote
36 views

### How to read instrument's range graph

I have an Agilent 4980 LCR meter and in its manual it has several graphs indicating the effective measurement ranges for each scale, like the one below: How to read such a graph to be sure that the ...
452 views

### Choosing a digital oscilloscope for a self learner [closed]

I'm about to start a course about electronic interfaces. My intention is to learn to debug hardware by doing measurements etc. with oscilloscopes and multimeters. According to the course, the ...
• 965
174 views

### exceeding an analog ammeter printed scale

I have a ~\$10 DC ammeter I mail ordered however long ago, on the display is printed Dagatron 7203 and on the lower right side of display is an upside down U ...
• 131
9k views

### Why only sine waves?

I have already read a few EE texts where a sine wave is often seen. Why is the sine wave often used as a test function for a circuit or a system? Why don't we use any other signal instead of sine? ...
• 437
173 views

### Instrumentation Amplifier Reference Node - Integrator vs Buffer

When looking at INA topologies (lets take AD8220 for example) I see examples of integrator or buffered resistor dividers used. What are the disadvantages of using an integrator? Both typologies ...
• 4,499
656 views

### Purpose of resistor across op-amp inputs

The following (from TI app note slaa414a) is an active bias-T that sums the AC and DC inputs to drive a load for the purpose of testing PSRR. What does the 100 Ohm resistor across the inputs do? Both ...
• 796