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A Discussion about Precision and Accuracy Precision and accuracy are two terms used interchangeably by the general population. The precision of a measurement is determined by how reproducible that measurement value is. The accuracy of a measurement is the measure of how the answer compared to reality. You need both to have a true measurement.
Precision: For example, if a sample is weighed by a student to be 42.58 g, and then measured by another student five different times with the resulting data:
Data: 42.09 g 42.15 g 42.10 g42.16 g 42.12 g No comment can be made about the accuracy of the measurements as the actual value is not known. The second student's values however only range between 42.09 and 42. 15 grams giving a variation of only 0.2% between the high and low observed values. The first student would exhibit good precision but still be wrong because his data set is not accurate. As to what makes a device precise: * It should be sturdy so that components are not twisted out of alignment * It should be constructed to standards and tolerances that are known and can be monitored
* It should be stable in a wide range of temperature and humidity or capable of maintaining known temperatures and humidity * It should be accompanied by a QA/QC and PM program
Accuracy:
The accuracy of a measurement is determined by how close a measured value is to its "true" value.For example, if a sample is known to weigh 3.182 g, and then weighed five different times by a student with the resulting data:
Data: 3.200 g 3.180 g 3.152 g3.168 g 3.189 g
Then the most accurate measurement would be 3.180 g, because it is closest to the "true" weight of the sample. The precision of the data is another issue. The values range between 3.152 g and 3.200 g. a range of .05 g or almost 2% difference between the high and the low. The second student is not precise but has stumbled across an almost correct answer. He is in no position to know which of his answers is correct.
As to what makes a device Accurate: * It should have internal or external standards for zeroing and full range measurement * It should be part of periodic QA/QC programs for Accuracy * It should meet the criteria for Precision
Non-Laboratory Examples:
If a carpenter built a house with a non-Accurate tape measure every room would be square and by his tape the exact right size. He would be precise. However, when it came to install a 4' x 8' rug in his 4' x 8' room it would not fit as he was not accurate.
If a cook has an oven that has a bad temperature control, it is not precise. If he wants to cook cakes at 375o F for one hour. The cakes will be burnt sometime and underdone at others
What else can I help you with?
How accurate you measure the thickness?
The accuracy of measuring thickness depends on the measurement tool used, such as calipers or micrometers, which can provide precision to within 0.01 mm or better. Additionally, proper technique, consistent pressure, and environmental factors like temperature and material properties can influence measurement accuracy. Calibration of the measuring instrument is also essential to ensure reliable results. Overall, achieving high accuracy requires careful attention to both tools and methods.
How should the final answer be expressed so that it can be measured by all measuring tools used?
The final answer should be expressed using appropriate units of measurement that are universally understood, such as meters, grams, liters, etc. It should be presented with the level of precision indicated by the measuring tools used, and any uncertainties or margins of error should be clearly stated. This ensures that the measurement is accurate, consistent, and comparable across different measuring tools.
What are measuring devices use by bakers in the bakery?
Bakers commonly use measuring cups, measuring spoons, kitchen scales, and thermometers to accurately measure ingredients in a bakery. These tools help ensure consistency and precision in recipes, leading to better quality baked goods.
Why inside and outside callipers called semi precision tools?
Inside and outside calipers are considered semi-precision tools because they provide a way to measure dimensions with reasonable accuracy, but lack the fine-tuning and precision of more advanced measuring instruments like micrometers or digital calipers. They are primarily used for comparative measurements, which means they can determine the relative sizes of objects but may not provide exact measurements. Their construction typically involves simple mechanical components, making them more suitable for less critical applications where extreme precision is not required.
What are tools for measuring of length?
Tools for measuring lengths are : Screw gauge, vernier calipers,drafter, ruler ,circular scale ,etc . These tools are used for measuring lengths according to their different least counts.
Give two reasons why precision measuring tools are not always accurate?
Precision measuring tools may be affected by wear and tear over time, leading to inaccurate readings. Additionally, external factors like temperature variations or improper calibration can also contribute to inaccuracies in precision measuring tools.
What is something that is accurate?
Precision measuring tools such as micrometers are accurate
What are the classification of measuring tools?
Measuring tools can be classified into several categories based on their purpose and functionality, including linear measuring tools (like rulers and tape measures), angular measuring tools (such as protractors and inclinometer), and volumetric measuring tools (like graduated cylinders and measuring cups). Additionally, they can be categorized based on precision, with tools ranging from basic measuring devices to high-precision instruments like micrometers and calipers. Another classification considers the method of measurement, distinguishing between analog and digital tools.
How do gauge blocks work and what is their primary function in precision measurement?
Gauge blocks are precision tools used to measure the accuracy of other tools. They work by being stacked together to create a specific height, which can then be used as a reference for measuring other objects. Their primary function in precision measurement is to provide a standard for calibrating and verifying the accuracy of measuring instruments.
What is measuring tools in baking?
Measuring tools in baking are essential utensils used to ensure accurate ingredient quantities, which is critical for successful recipes. Common measuring tools include dry measuring cups for solids, liquid measuring cups for liquids, and measuring spoons for smaller amounts. Precision is key in baking, as even slight variations can affect texture and flavor. Using the right tools helps achieve consistent and reliable results in baked goods.
What is the main business of the company Browne and Sharpe?
The main business of the company Browne and Sharpe is mainly focused on meteorological equipment tools and technology, such as precision measuring tools, cutting tools and pumps.
Campaign tools designed to influence public opinion rather than measuring it are?
Push polls
How accurate you measure the thickness?
The accuracy of measuring thickness depends on the measurement tool used, such as calipers or micrometers, which can provide precision to within 0.01 mm or better. Additionally, proper technique, consistent pressure, and environmental factors like temperature and material properties can influence measurement accuracy. Calibration of the measuring instrument is also essential to ensure reliable results. Overall, achieving high accuracy requires careful attention to both tools and methods.
What are the precision measuring tools?
Precision measuring tools are instruments used to measure small distances, angles, or quantities with a high degree of accuracy. They are commonly used in industries like manufacturing, engineering, metalworking, electronics, and laboratory research. Common types of precision measuring tools include: Vernier Calipers Used to measure internal, external dimensions and depths with fine precision—typically up to 0.02 mm accuracy. Micrometers Ideal for measuring very small thicknesses or diameters of objects—especially in mechanical and engineering work. Dial Indicators Used to check the alignment or straightness of parts and surfaces in machine shops. Height Gauges Used in workshops to measure vertical distances or heights with high accuracy, especially during machining. Bore Gauges Helpful in measuring the internal diameter of holes and cylinders to tight tolerances. Coordinate Measuring Machines (CMMs) Advanced computer-controlled tools that precisely measure the geometry of complex components in 3D.
What factors does the choice of a length-measuring device depend?
The choice of a length-measuring device depends on several factors, including the required precision and accuracy for the measurement, the range of lengths to be measured, and the environmental conditions (such as temperature and humidity) that could affect the measurement. Additionally, the ease of use, portability, and cost of the device play significant roles in the decision-making process. Finally, the specific application or industry requirements may dictate the need for specialized measuring tools.
What are four categories of hardware tools explain?
Four categories of hardware tools include hand tools, power tools, measuring tools, and fastening tools. Hand tools, such as hammers and screwdrivers, are operated manually and are essential for basic tasks. Power tools, like drills and saws, use electricity or batteries for enhanced efficiency and precision. Measuring tools, such as tape measures and calipers, ensure accuracy in dimensions, while fastening tools, like wrenches and pliers, are designed to join materials securely.
What are four measuring tools used in a workshop?
What are four measuring tools used in the workshop
