What are the factors that cause experimental errors, and what are the possible causes of errors in e

The factors of experimental error, human factors, measuring factors, force factors, and measurement factors.

1. Human factors.

Errors due to human factors, including misreading, miscalculations, and parallax.

Wait. Misreading often occurs with the cursor.

Rulers, centimeter cards and other measuring tools, vernier scale is easy to cause misreading of a minimum reading. If it is often misread as mm or mm at mm, the centimeter card scale is easy to misread a pitch.

, e.g. mm is often mispronounced as mm or mm.

2. Measuring tool factors.

Errors caused by gage factors, including scale errors, wear errors, and uncorrected before use. Whether the scale division is accurate or not, must be corrected and traced by a more sophisticated instrument, and the measuring tool will produce a considerable degree of wear after a period of use, so it must be calibrated or sent for repair before it can be used again.

3. The strength factor.

Errors due to the contact force used in the measurement or the deflection caused by the contact, according to Hooke's law.

When measuring the size, if the measuring shaft is in contact with the machine with a certain measuring force, the shaft and the machine will be partially or comprehensively elastically deformed, in order to prevent this elastic deformation, the measuring shaft and the machine should be made of the same material.

4. Measurement factors.

Errors caused by poor instrument design or placement during measurement, including cosine error, Abbe error, etc.

The factors that cause errors in the test can usually be considered in the following aspects:

1. When different people conduct the same test, because of the subtle differences in techniques, the error in the test results will be caused. Therefore, in experiments that do not require a large number of manual operations, the same person needs to operate, so that the data produced are more comparable;

2. Machine, equipment and instruments, here it is necessary to consider whether there is an error in the test instrument itself. Usually, the instruments and equipment of the laboratory are calibrated and verified every year. Before the test, you can check the equipment with reference materials to see whether the accuracy and error of the equipment meet the needs of the test itself;

3. Matter, test sample, usually before the test sample must be adjusted in the state, so that the test sample can reach a stable physical state. It is recommended to store the sample in an environment of 23 degrees Celsius, 50 degrees Celsius for more than 24 hours;

When measuring. Since various factors will cause a small error, these factors must be understood and effectively solved in order to minimize the error in the whole measurement process. When measuring, the main causes of errors are systematic error and random error, and the systematic error has the following situations:

Misreading, miscalculation, parallax, scale error, abrasion error, contact force error, deflection error, cosine error, Abbe error, thermal deformation error, etc.

The magnitude of the systematic error is constant during the measurement process, which can be calculated or experimentally obtained, that is, it can be corrected or adjusted to reduce it. These factors are grouped into five broad categories, which are described in detail as follows: Human factors.

The above content refers to: Encyclopedia - Experimental Error.

Quantity and concentration experiment of substances - constant volume error analysis.

As follows:

a) Errors in the process of temperature determination: In the process of temperature determination by attitude roll, it is impossible to achieve absolute uniformity of the temperature of all parts of the system due to the stirring of the agitator. Therefore, the temperature of the liquid near the temperature probe is measured by the temperature measuring instrument, which may not be exactly the same as the temperature of the saturated vapor, so that there is an error between the measured data and the final calculation and the actual value.

b) Error caused by the change of environmental conditions in the experiment: In the measurement process, although the temperature of the system is kept constant by using a thermostatic bath, it is still not completely guaranteed that the measurement conditions have not changed.

At the same time, because the measuring instrument is in direct contact with the external environment in the experiment, when the external environmental temperature, atmospheric pressure and humidity change, the difference in the state of the measuring instrument may affect the accuracy of the measured data.

c) Change of measurement system: In the trace skin experiment, it was found that the composition of the measurement system did not change, and it was always absolute ethanol. However, in practice, there is also the possibility of a change in the composition of the system.

Specifically, if the liquid boils too vigorously during venting or heating up, the evaporated liquid may dissolve the glycerin used to seal the grinding mouth of the instrument.

Later, when the steam mixed with glycerol returns to the system, the composition of the system may be changed, so that the saturated vapor pressure of the system changes, and errors are introduced. In order to avoid this phenomenon, the piston H should be adjusted at any time to prevent the liquid from boiling violently.

I've had a similar problem before == pasted it over.

Generally speaking, based on personal experience, the most common errors are 0 0

The first is the equipment error.

1) For example, the accuracy of the instrument or something. Generally, if you need to calculate, the teacher will give you numbers and formulas, and then let you calculate.

2) For example, the aging of the instrument will lead to the inaccuracy of the measurement ==

Then there is the environmental error.

This is mainly the influence of temperature and humidity on the measurement results. For example, this effect is taken into account when measuring air density

There is also personnel error.

1) The error of the calculated result caused by the significant figures at the time of calculation.

2) Errors in readings. For example, looking up and looking down or something is not accurate =.=

3) For example, because the prediction is not accurate, the measured data does not reflect the whole experimental process well. That is, there is no normal distribution 0 0

There are also some according to the actual situationFor example, when doing a collision test, the velocity is not accurate because of air resistance and friction.

The error is mainly caused by the following factors:

1. Some fixed and unchanging systematic errors. For example, the weight of the weight is uneven, the perpendicularity between the afterburner arm and the cylinder, the inaccuracy of the geometric size, the resistance of the long wire, the sensitivity coefficient error of the strain gauge, and the residual strain will all affect the experimental accuracy.

2. The loading is uneven, resulting in reading error. Because the lever loading mechanism and the thin-walled cylinder are combined, when the lever is not horizontal, the knife edge and the knife pad on the lever fulcrum, the knife edge and the knife pad of the lever are not perpendicular to each other, and the line of action of the rolling mu load is tilted, and the combination of bending and torsion can not be realized intact.

In an experiment, error refers to the difference between the measured result and the true value. Errors can be caused by a variety of factors, and here are some common experimental errors:

Random error: Random error is caused by factors such as uncertainty of the measuring instrument, environmental interference, or subjective judgment of the observer. It is an irregular, unavoidable error that can discreet results from multiple repeated measurements.

Systematic error: Systematic error is caused by factors such as inherent deviation of the experimental instrument, deviation of the operating method, or defects in the experimental design. It is a regular, fixed error that can cause all measurements to deviate from the true value.

Human error: Human error is caused by factors such as the technical level, visual judgment or operation error of the experimental operator. For example, visual fatigue during readings, the ability to grasp a measuring instrument, etc., can introduce human error.

Instrument error: The error of the instrument is caused by factors such as the accuracy, sensitivity, calibration and inaccuracy of the measuring instrument. If the instrument used is low in measurement accuracy or not calibrated, large instrument errors may be introduced.

Environmental Errors: Environmental errors are caused by changes in environmental conditions. For example, changes in environmental factors such as temperature, humidity, pressure, etc., may have an impact on the results of an experiment.

In order to reduce the error and improve the reliability of the experiment, some measures can be taken, such as making multiple repeated measurements to reduce the impact of random error, using precision instruments and calibrating them regularly to reduce instrument error, and paying attention to the standardization and consistency of experimental operations to reduce human error.

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During data processing and analysis, statistical methods can also be used to evaluate and correct errors, such as calculating mean, standard deviation, confidence interval, etc.

It should be noted that although errors are inevitable, reasonable experimental design and rigorous experimental operation can reduce the impact of errors and improve the accuracy and reliability of experimental results.