Questions tagged [accuracy]

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4answers
366 views

Confused with the effect number of decimals at the output of transducer

There is an ultrasonic device which measures and outputs both wind speed and direction and has a very long manual. But to keep it short and summarize, the accuracy and the resolution for the wind ...
0
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1answer
34 views

How to relate the sampling frequency to the measurement error for this kind of pulse period measurements?

I sample a zero to 400Hz varying pulse train at 4kHz and post-process this pulse train data by MATLAB to obtain each single pulse's period. So for instance below represents a 0 to 6V pulse. The green ...
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3answers
74 views

measurement errors: add up or cancel out?

Take an accelerometer, or a hall sensor, or a thermometer, or any sensor. It will have an accuracy, which means the readings will contain some error of this sort. My guess is that by taking a big ...
0
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1answer
32 views

Calculate measurement accuracy of voltage divider with suppressor diode?

I have a voltage divider to measure the voltage in a DC Bus. I parallel to R1 I have a suppressor diode (D1) to protect the input of the microcontroller from transient overvoltages. This diode has a ...
0
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1answer
39 views

DC motor accuracy with encoder

I am building a coil winding machine and I've already set up something that works. I used two nema17 stepper motors and tb6600 stepper driver cards. The problem is that motors are seems to overheating ...
1
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1answer
109 views

Set the Gain of an Opamp Accurately Using a Potentiometer

I want to set the gain of an opamp accurately using an potentiometer, with low thermal drift and good long-term stability. From what I've read, there are three basic ways of doing it, but none of them ...
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0answers
74 views

PPS Timer on STM32

The MCU used is a STM32F042 which is clocked by an OCXO oscillator (Abracon 10 MHz - 20 ppb). The subject of this thread is to get the best accuracy on one PPS Timer. For my application, I need to ...
0
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3answers
83 views

GPS relative positioning

I have a set of 4 rovers crawling on the ground, each of them equipped with a standard GPS positioning system. The rovers start together from a known position. Each rover is locating itself via GPS. ...
6
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1answer
393 views

Why is my 10k NTC thermistor on average accurate to 2C

I am trying to figure out what is causing the 2C inaccuracy in my thermistor calibrations, my goal is to get my accuracy down to > .1C. I am using the KS103J2 10K NTC thermistor. To calibrate my ...
1
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1answer
35 views

Finding out the accuracy of the current probe's measurement

As part of power supply testing we are measuring the current profiles of various regulators. Startup profiles includes current bursts with different current amplitudes and widths. i want to ...
2
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2answers
129 views

Question about the accuracy of integrated resistors

I'm studying the implementation of resistors in integrated technology. In particular the books deals with the accuracy of the obtained resistors. It says: Then it says: "We observe that the value of ...
0
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1answer
84 views

Load cell accuracy: rated output vs. full scale

I'm currently shopping for some subminature load cells for a research project. I've narrowed it down to two options, the FUTEK LCM100 and the Burster Model 8417. Problem is the two specify their ...
1
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1answer
261 views

Measure sensitivity of ADC

I would like to benchmark my ADC. I can calculate a sensitivity value based on the information in the datasheet. However, I would like to measure/benchmark this figure. Is there a standard method ...
8
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6answers
1k views

Would reducing the reference voltage of an ADC have any effect on accuracy?

Regarding the following information taken from a paper: The paragraph is telling about what happens when the ADC Vref is reduced. There is the statement from the above quote: Note that if you ...
6
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2answers
996 views

Precision notation for voltmeters

From the technical details of a multimeter: AC Voltage: - Range and Accuracy: 200mV ± (1.0%+2); 2V ± (0.7%+3); 20 ± (1.0%+3); 200/600V ± (1.2%+3) What does the notation "± (0.7%+3)" mean? ...
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1answer
35 views

Resistance measurement and standard uncertainty

In a text there is a section regarding a basic example for uncertainty calculation of a resistor. Here is the related part: Above the text uses the the accuracy of the current source and the ...
0
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2answers
281 views

How accurate are flex sensors?

So for the project I am working on I plan on measuring very precise changes in angle, possibly up to 5 degrees of accuracy. Are polymer ink sensors (the classic Nintendo power glove flex sensor) the ...
1
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2answers
71 views

Problem understanding impedance measurement device accuracy format

I am reading the datasheet of an impedance measurement device. Its accuracy is listed as '±0.4% rdg. ±8 dgt.'. What does 'rdg.' and 'dgt.' mean? And how should I interpret the accuracy? The device is ...
1
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1answer
149 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) ...
0
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1answer
83 views

Multimeter temperature coefficient - Specified accuracy

I want to calculate the temperature coefficient for a digital multimeter. The datasheet I read it is calculated as: 0.1*(specified accuracy)/°C (<18°C or >28°C) Do you know what specified ...
6
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1answer
119 views

GPS L5C Differential? Max Update Rate(bits/s|Hz)?

The differential GPS chips use L1 and L2C to calculate the ionospheric interference. With the new GPS satellites, the new band L5C is being deployed, and I am wondering about the following things: ...
3
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1answer
130 views

PWM nonlinearity

simulate this circuit – Schematic created using CircuitLab I am using the PIC16F1786 in a current transducer to measure 0-1 Amp DC. I use an A/D converter to measure voltage from a Hall Effect ...
1
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2answers
59 views

Confusion about the meaning a parameter

Below is a part from this accelerometer: For +/-2g the Scale factor tolerance is given as 10mg. There is also 0.25%. This is in parentheses as 1.25(0.25%) V/g. Is 10mg derived from 1.25(0.25%) V/g? ...
0
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1answer
53 views

passive probes and accurate measurements

I have read somewhere that if we have a 100 MHz oscilliscope then we can measure only the waveform of 10 MHz accuratley with an error of 1%. My question is that if passive probes are used then will ...
2
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2answers
269 views

Sigma Delta ADC vs SAR ADC, for multiplexing signal

We are using PIC32MZ series Microcontrollers for our energy based application where we are measuring voltage and current for electric consumers. One single meter can monitor current for upto 10 ...
2
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2answers
337 views

Confusion about accuracy vs tolerance of an operating resistor

Let's say I bought a 100 Ohm resistor from a manufacturer with a tolerance of 10%. What I understand from the term tolerance here is that: it is the amount that a resistor may initially vary from its "...
0
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1answer
295 views

Understanding Pressure MEMS Technical Information (Relative and Absolute Accuracy)

In my research, I use smartphones pressure sensor data, and I need to understand their errors and limitations. I found the technical chart for the sensor: But I don't really understand the meaning of ...
4
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3answers
826 views

More accuracy from analog multiplication?

Let's say I want to detect a voltage signal that's guaranteed to be between 0V and 1V through an ADC whose upper range is 5V. I can hook the signal up to the ADC directly, but then I'll only be using ...
0
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1answer
106 views

Real time clock MCP7940N I2C interface

The RTC MCP7940N is used in the system. The microcontroller and RTC MCP7940N are connected through the I2C interface. I would to know what is the better design to read the timer value from the RTC. ...
8
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4answers
2k views

Accuracy of a multimeter over 10 years period

Datasheets of multimeters contain accuracy specifications. One parameter is usually accuracy over period of 1 year. I understand that it means multimeter can be off by the specified value. For ...
-1
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1answer
129 views

How can we achieve position accuracy with simple worm gear box. [closed]

I am also proposing to use simple 40:1 ratio worm gear box with Input servo motor. I am having a dial of 1600mm diameter on output of the gear box which will rotate only in clockwise direction at max ...
0
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1answer
122 views

How to calculate 50Hz active power measurement accuracy from datasheet?

The R&S HMC8015 power analyzer datasheet and technical data list: Range configuration ...
0
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3answers
80 views

What are the advantages of a internal high-precision oscilator over an external one

Many lab measurement equipment for analog, radiou and RF purposes, such as frequency counters, arbitrary signal generators, oscilloscopes, etc. have the option to input an external reference clock (...
0
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1answer
165 views

Increase accuracy of ADC without device AGND

I am using the ADC of the PIC16F18344 — http://www.microchip.com/wwwproducts/en/PIC16F18344 It has neither Avdd nor Agnd, but it does have selectable Vref+ and Vref- pins. If I were to stop using ...
0
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1answer
170 views

resistor array matched accuracy

I need 4 accurately matched resistors for my circuit, I heard resistor arrays have better matching quality. but I don't know what parameter to look for in the datasheets. all I see is Tolerance. I don'...
1
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2answers
62 views

what parameter should be noticed in design sample and hold circuit?

if I want to sample from a pulse with 50kHz frequency, that changing between -5 and +5 Volt, what parameter should be considered in choosing op amp to get high accuracy, and How should I calculate my ...
0
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1answer
2k views

How to have an accurace ADC?(STM32)

Today I was reading the datasheet and refrence manual of STM32. As others, I think we should use the power creativeness which god has gifted us to have an accurace ADC. :) Here are the datasheet and ...
0
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1answer
59 views

What kind of information can be assumed from sensor accuracy graph

I'm using a MS5803-15BA (datasheet) to make pressure measurements. The datasheet contains this graph of pressure error vs. pressure at page 17. The datasheet also specifies on page 1 that the ...
1
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2answers
296 views

Necessary Read Frequency vs PPR of Rotary Encoder

I am working on a microcontroller (ATMega328) project where I am planning to use a rotary encoder. I plan to have a non-time critical main loop and set up a timer interrupt to handle reading the ...
0
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2answers
1k views

Accuracy error of ammeter from specification : is it really just a constant offset?

On ammeter specifications it is often written accuracy specification $$ (....\% rdg+ ... digits) $$ While the ammeter can have a certain last digit on the screen, which determine the resolution if ...
3
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1answer
2k views

DC motor RPM accuracy/precision

Small, permanent magnet, brushed tri-phase DC motors ('toy motors') may give a speed/torque curve, or at minimum a no load RPM. What is typical RPM accuracy relative to the datasheet, and how precise ...
0
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0answers
221 views

unstable magnetometer readings

I did the magnetic calibration here on the LSM303DLHC for a field roughly 48 uT. The method seems to have worked in that the combined bias (b) values went from ...
1
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2answers
620 views

Accuracy of various elements in circuit

Every op-amp has error. We all know that. So logically, the more op-amp used, the less accuracy we will have, right? In the circuit ,there are 2 parts: first is the current to voltage converter, ...
0
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1answer
87 views

Component manufacturing and placement accuracy/precision

I am involved in a community project where I need to employ computer vision on common smartphone models (Samsung Galaxy S 5/6/7, iPhones etc.). Doing that involves calibrating the phone's camera for ...
0
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1answer
1k views

Change internal voltage reference on an STM32L0

I'm using a Nucleo board with an STM32L073RZ. With an "AnalogIn" object on PA_0, I measure the voltage of a TMP36 (temperature sensor), but the accuracy is not great at low temperature. I want to ...
0
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2answers
122 views

load cell number and accuracy

I want to measure weight, so I use load cells, As far I know, commonly 4 load cells are used for this purpose, but I can not understand it's real purpose, maybe 2 will be more accurate than 4? Is it ...
0
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1answer
555 views

why resolution lower than accuracy

Regards, I've seen a few sensors which its datasheet claims to have a better resolution than the mean accuracy. I understand resolution as the lower identifiable value of the measurement; and, as ...
0
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3answers
3k views

Is the 555 timer accurate and uniform enough for a metronome?

I would like to create a simple metronome using the ICM7555 CMOS RC timer (datasheet), but I am not sure if the pulses will be "uniform enough". The datasheet states "astable timing accuracy" of 2% /...
0
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4answers
853 views

accuracy shunt resistor beter than 0.1%? [closed]

I want to make a circuit that can measure a current more accurate then 0.1%. For instance if I measure 7A, I want to be able to read 7.000 A. If I use a 0.1% shunt resistor I do not know if it is 7....
0
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1answer
452 views

How to measure bipolar analog signal accurately (to 1mV) on raspberry pi

BACKGROUND This is my first question on Stack Exchange so apologies for any missteps. I'm currently working on a project measuring tilt outputing an analog signal that ranges from -2V to 2V. But the ...