Is the absolute error the same when measuring something with the same tool?

The absolute error is the difference between the measured value and the theoretical value.

Its use of the same tool to measure can only indicate that the systematic error is the same. Even if the influence of the measurement environment is not taken into account, each measurement reading will have a different measurement value due to human error, which is called accidental error. Therefore, the absolute error of each measurement is naturally different, that is, there will be a different measurement result for each measurement (with a small range of fluctuations if the method is correct).

Finally, move on to the main point:

In fact, the error is a statistic, and it cannot be determined by a limited number of measurements. When measuring something with the same tool, because the accidental error is a constant, if the environment is the same (the measurement is carried out in the same environment), and the tool is the same, it should be said that if you measure something in this case, you will get the same measurement accuracy.

The question you asked is not right, the same item measures the same thing, but measures at different times, maybe the data is different, this is an accidental error, it is equivalent to the same two leaves in the world, as long as the error exists, then the measurement results are different, but as long as the error is within the allowable range, then the measurement results can be applied.

1. The measured value is: 500ml The actual value is: Absolute error is the difference between the measurement result and the true value, and the absolute error of the measured value is the true value.

2. The relative error is the ratio of the absolute error to the measured value, the ratio of the commonly used absolute error to the value of the instrument, expressed as a percentage, and the relative error (absolute error meter value) is 100%.

3. So according to the above formula: absolute error =. Relative error = .

Absolute error. is the absolute value of the difference between the measured value and the true value.

i.e. absolute error = |Measured value - true value |; Relative error = .

is the percentage of the true value of the absolute error, i.e., the relative error = |Measured value - true value |; True value.

Absolute error is the value that indicates both the magnitude of the error and its positive and negative directions, and reflects the magnitude of the deviation of the measurement result from the true value in the same unit dimension, which accurately represents the actual magnitude of the deviation from the true value.

The relative error is equivalent to the absolute error of the measurement as a percentage or order of magnitude of the true (or given) value.

means that it is dimensionless.

value. In general, the relative error is a better indicator of how confident the measurement is.

It is true that the measurement error can be expressed in both absolute and relative errors.

Measurement error refers to the difference between the measured value read by the meter and the true value being measured. The two expressions of measurement error are absolute error and relative error.

1. Absolute error refers to the difference between the measured value and its true value. A magnitude equal to the absolute error, but with opposite signs, is called a correction. Absolute error can only indicate the deviation of the measurement result from the actual value, and cannot accurately reflect the accuracy of the measurement.

2. Relative error refers to the ratio of the absolute error to the true value being measured. The relative error is the ratio of two quantities of the same dimension, with only magnitude and sign. The ratio of the absolute error to the full scale value of the instrument is often used in measurements to express the relative error, which is called the reference relative error.

A measuring instrument is expressed in terms of its accuracy using the maximum reference relative error, which reflects the magnitude of the instrument's overall error.

Electrical instruments are generally divided into 7 levels: ,, when the accuracy level of the instrument is determined, the closer the indication value is to the range, the smaller the relative error of the indication value. Therefore, when measuring, it is necessary to pay attention to the selection of the range, and try to make the instrument indication in the area above 2 3 of the full degree value.

** of the measurement error.

1. Instrument error is the error introduced by the measuring instrument itself and its accessories. For example, errors caused by zero drift of the instrument, inaccurate scales, etc.

2. Influence error refers to the error caused by the inconsistency of environmental factors such as temperature, humidity, vibration, power supply voltage, electromagnetic field and instrument requirements.

3. Method error refers to the error caused by unreasonable measurement method.

4. Personal error refers to the error caused by the surveyor's resolution, visual fatigue, bad habits or lack of responsibility, such as reading the wrong number and improper operation.

5. The change error of the measurement object refers to the error caused by the inaccuracy of the measurement value due to the change of the measurement object in the measurement process.

Causes of measurement errors:

The practice of measurement work shows that there are measurement errors in the observations, or rather, measurement errors are inevitable. The causes of measurement errors can be summarized in the following three aspects:

1) Human causes. Due to the limitations of the observer's ability to distinguish sensory organs, errors will occur in the centering, leveling, aiming, and reading of the instrument. In addition, the technical proficiency of the observer will also have different degrees of influence on the observation results.

2) The reason for the instrument. Each measuring instrument only has a certain degree of accuracy, so the measurement results are affected to a certain extent.

3) The influence of the external environment. The objective conditions such as air temperature, wind, sunlight exposure, atmospheric refraction, and smoke in the external environment are constantly changing, so that the measurement results are incorrect.

People, instruments and the environment are necessary conditions for the measurement to be carried out, but these observation conditions have their own limitations and disadvantages to the measurement. Therefore, errors in the measurement results are inevitable.

The relative error is the ratio of the medium error to the observer. For example, the error of measuring a distance of 100 meters is 2 centimeters, and the error of measuring 1000 meters is also 2 centimeters, so the error of the middle error cannot reflect the accuracy of the two measurements, and the relative error needs to be used.

What do these nouns mean? How it's calculated. Please do me a favor! Don't hesitate to teach, thank you The absolute position then the fragment point has an absolute position error (in the Xi'an 80 coordinate system in the position error, to Xi'an.

The relative error is the ratio of the absolute error of the measurement to the agreed truth value of the measurement. Multiply by 100% to get the numerical value, expressed as a percentage.

The medium error is not equal to the true error, it is only a representative value of a set of true errors. The magnitude of the neutral error reflects the accuracy of the group of observations, so the neutral error is usually called the neutral error of the observations. Also known as "standard deviation", it is very sensitive to the reflection of extra-large or extra-small errors in a set of measurements, and can well reflect the fluctuation of measurement results.

This is why standard deviation is widely used in engineering surveys.

It is divided into two categories: 1. Absolute error.

2. Relative error, including:

1) Actual relative error.

2) Relative error of the indication value.

3) Relative error of fullness.

4) Decibel error.

From the point of view, the error can be divided into two types: systematic error and accidental error. It is also divided into three categories: systematic error, accidental error and gross error.

1. The gross error is generally caused by human reasons, strictly speaking, it is a kind of error, which cannot be regarded as an error and can be completely avoided.

2. Systematic errors are caused by the inaccuracy of the instrument itself, or the rough experimental method, or the imperfect experimental principle. The characteristic of systematic error is that when the same experiment is redone many times, the error is always the same large or small, and there will be no situation where this time is too large and the other time is small. In order to reduce the systematic error, it is necessary to calibrate the measuring instrument, improve the experimental method, and design the experiment that is more complete in principle.

3. Accidental error is caused by the influence of various accidental factors on the experimenter, measuring instrument and measured physical quantity. Accidental errors are always sometimes large and sometimes small, and the probability of being too large or too small is the same. As a result, it is possible to take several more measurements to find the average of the values that have been measured several times, which is closer to the true value than the values measured in one time.

Two categories. Absolute error, relative error.

Measurement errors can be reduced, but they cannot be eliminated, and the difference between errors and errors is that errors cannot be avoided but errors can be avoided.

Errors are different from mistakes, which should and can be avoided, whereas errors cannot be avoided absolutely. From the principle of the experiment, the instrument used in the experiment and the adjustment of the instrument, to each measurement of physical quantities, there are inevitably errors, and throughout the whole experiment.

Absolute error--- Let the true value of a measurement n be n and the error is =|n'-n|, which reflects the magnitude by which the measured value deviates from the true value, which is called the absolute error.

Relative error--- The size of the actual error in the measurement is called the absolute error, and the ratio of the absolute error to the measured value is called the relative error.

The absolute error and the measured value n have the same unit.

It is impossible to compare the reliability of different measurement results with absolute error, so people use the ratio of the absolute error of the measured value to the measured value to evaluate it, and call it relative error, which can be reduced into percentages, also called percentage error. For example, the length of two objects is measured with an outer diameter micrometer, and the measured length is millimeters and millimeters respectively, and the absolute error of the two measurements is 0 01 millimeters, from the perspective of absolute error, the evaluation of the two measurements is the same, but the relative error of the former is, the latter is 10%, and the relative error of the latter is 100 times that of the former.

Simply put, absolute error is the deviation of a measured value from a true value (or theoretical value, or set value); The relative error is the relative difference between the two measurements.

If the absolute error of the sieve residue result is greater than that of two sieves, it should be redone once". That is, the measured value and the theoretical value should not be too discrete, so that the experiment is not representative.

I didn't look at the corresponding test criteria, and speculated that this is what it means, and it should be on the drop.