• Unit error. Meniscus Error. Since water molecules are attracted to the sides of the measuring cylinder and this force. decreases with distance from the sides, water has a downward curving surface or. MENISCUS.
What is a meniscus and why is it important?
The meniscus plays two important roles within the knee. A meniscus is a critical shock absorber within the knee . The meniscus also provides stability within the knee.
What is meant by parallax error?
The error/displacement caused in in the apparent position of the object due to the viewing angle that is other than the angle that is perpendicular to the object.
What is a meniscus and how is it used?
A concave surface of a liquid resulting from surface tension. The bottom of the meniscus is used to measure the volume of a liquid in apparatus such as a graduated cylinder.
What is the name of the error due to reading the meniscus from the wrong position?
Parallax is a deceptive change of the position of an object which is observed while the position of the observer changes. Position of eye at all volumetric vessels must be at the same level as the meniscus. If not, the parallax will cause an error while reading the position of the meniscus of a liquid in a burette.
Which meniscus is more important?
The posterior horn of the lateral meniscus includes the main body of the lateral meniscus, posterior to the popliteus tendon, and its root attachment on the posterior aspect of the tibia. The lateral meniscus is even more important than the medial meniscus for shock absorption.
How important is your meniscus?
The meniscus has an important function inside the knee as a shock absorber that helps distribute the load of the body . If the entire meniscus is removed, the rest of the joint gets overloaded and the knee is susceptible to arthritis. This is why the surgeon will save as much of the meniscus as possible.
How do we avoid parallax error?
- Orientation of eyes should be in a straight line. ...
- Place the measuring device on its edge. ...
- Use a fine-edged device. ...
- Read the lower meniscus of liquid to get an accurate measurement. ...
- Take the average of readings.
Is parallax error a human error?
Random errors are errors made by the person carrying out the measuring, and are usually down to timing incorrectly, or reading the instrument incorrectly. ... Reaction time errors and parallax errors are examples of random errors.
What is another name for parallax error?
Also called “ viewfinder error ,” it is the difference between what you see in a camera’s viewfinder and the final picture.
How is a meniscus read?
A meniscus occurs because of surface tension in the liquid and must be read at eye level . For a concave meniscus, the correct volume will be read at the bottom of the curve. For a convex meniscus, the opposite is true and the correct reading will be at the top of the curve.
Why does a meniscus form?
Why a meniscus occurs
Adhesion is responsible for a meniscus and this has to do in part with water’s fairly high surface tension. ... And since water molecules like to stick together, when the molecules touching the glass cling to it, other water molecules cling to the molecules touching the glass, forming the meniscus.
Why do we need to read the lower meniscus and not the upper meniscus?
Why do we need to read the lower meniscus and not the upper meniscus? The lower meniscus must be read while measuring the volume of colourless or transparent liquids but the upper meniscus while using colured ones because the phase boundary in the colourless liquid is clearly visible so it is easy to read it.
What are the 3 types of errors in science?
Errors are normally classified in three categories: systematic errors, random errors, and blunders . Systematic errors are due to identified causes and can, in principle, be eliminated. Errors of this type result in measured values that are consistently too high or consistently too low.
What type of error is measuring wrong?
Experimental error is the difference between a measurement and the true value or between two measured values. Experimental error, itself, is measured by its accuracy and precision. Accuracy measures how close a measured value is to the true value or accepted value.
What is the effect in the reading if the eye is below the meniscus?
The graduated cylinder is calibrated so that reading the bottom of the meniscus, when viewed at eye level, will give accurate results. Viewing the meniscus at any angle other than eye level will give inaccurate results. This graduate cylinder (below right) reads 24.3 ml.
