Questions tagged [accuracy]

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1answer
28 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 ...
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1answer
37 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 ...
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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
947 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
29 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 ...
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2answers
137 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 ...
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2answers
60 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 ...
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1answer
75 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) ...
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1answer
59 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
102 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
98 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 ...
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2answers
55 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? ...
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1answer
51 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 ...
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2answers
174 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 ...
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2answers
200 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 "...
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1answer
243 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 ...
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3answers
793 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 ...
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1answer
91 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. ...
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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 ...
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1answer
100 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 ...
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1answer
104 views

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

The R&S HMC8015 power analyzer datasheet and technical data list: Range configuration ...
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3answers
78 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 (...
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1answer
146 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 ...
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1answer
116 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'...
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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 ...
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1answer
1k 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 ...
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1answer
51 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 ...
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2answers
248 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 ...
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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 ...
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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 ...
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0answers
202 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 ...
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2answers
513 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, ...
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1answer
79 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 ...
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1answer
981 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 ...
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2answers
109 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 ...
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1answer
367 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 ...
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3answers
2k 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% /...
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4answers
666 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....
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1answer
400 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 ...
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2answers
68 views

Instrumentation: Measurement Noise

I have a Tektronix DPO2014 and I'm trying to get a feel for what I can expect in terms of precision and accuracy performance on a clean and stable voltage. I'd like to be able to accurately and ...
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1answer
78 views

which type of motor is best choice for rotating screw with 1 deg accuracy and under 1kgfcm torque? [closed]

I'd like to apply electric motor with small size. My application is rotating screw with 1 deg accuracy and under 1kgfcm torque. Which type of motor is best choice?
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2answers
442 views

Which of all available circuit simulators provide the most accurate results? [closed]

After learning a lot more, I've come to the conclusion that simulators are in fact limited. Let's use a phase shift oscillator as an example. In simulation, It worked perfectly(in nearly every ...
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2answers
755 views

GPS time accuracy (SIM808 or similar) - process between NMEA sentences and AT command response

In an SIM808 chip or similar you can get the GPS information with this AT command: ...
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3answers
560 views

Calculating power measurement error from V and I error margins

I am using a Yokogawa WT310 for measuring DC power. The manual (available here) says that both current and voltage have accuracy of +/-(0.1% of reading + 0.2% of range). Assume this example setup: ...
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2answers
340 views

What are the technical difficulties of making an accurate digital accelerometer?

In theory, double integrating accelerometer data with time should give displacement. However this is not widely practiced due to how susceptible accelerometer is to noise (and other reasons??), and ...
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1answer
111 views

Dual Digital Pot With Different Op amps & Layout

I'm using a dual digital pot IC controlled with an SPI interface. Each pot goes to a different op amp on the pcb to calibrate two different voltages. Since both pots are in the same package, how big ...
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1answer
2k views

GPS Accuracy - is it relative or absolute?

If a GPS unit reports accuracy to 1 meter, does that mean that the receiver's absolute location at any time could be up to 1 meter incorrect in any direction, -or- does it mean that the initial ...
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4answers
739 views

What is more accurate, thermistor's R-T table or Steinhart-Hart equation?

If I want the conversion of thermistor's resistance to temperature to be as accurate as possible, should I refer to a table or use the Steinhart-Hart Equation? I am in doubt because a table contains ...
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6answers
1k views

Statistical accuracy of multiple resistors in series or parallel

I'm having a senior moment and would appreciate clarity. I'm working on an inverting amplifier design where I need to add low-pass filtering and a voltage clamp. Without the filtering and clamp, the ...
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1answer
98 views

What means linear response for accelerometers?

What means that accelerometers measures linear acceleration and, in particular, that they are a linear response?