Classification of errors and elimination of error

Classification of errors and elimination of error

1. Gross error
2. Systematic error
3. Random errors

Gross errors:

Discourse of error mainly occur by human mistakes in reading the instrument recording and calculating the measurement results. This cause of errors mainly occurs by human mistakes in reading the instrument, recording and calculating the measurement results.

Example: the temperature is 31.5 degree centigrade but human may write 21.5 degree centigrade.

This errors can be avoided by two methods.

*Great care should be taken in reading and recording the data.

*2 to 3 readings should be taken.

Systematic error:

This types of errors can be divided into 3 categories.

(a) Instrumental errors

(b) Environmental errors

(c) Observation errors.

(a) Instrumental errors:

It occurs due to the misuse of errors and loading effect on the instrument.

This errors will also occur due to the calibration of errors.

Towards others we should celebrate the instrument regularly.

(b) Environmental errors:

This errors are caused due to the change in the environmental condition in the area surrounding the instrument. Such as changes in the temperature, humidity, pressure, magnetic field or electrostatic field.

This errors are reduced by sealing the certain components in instrument, which element the effect of humidity, pressure, temperature and magnetic field or electrostatic shield must be provided.

(c) Observation errors:

This errors are produced by the experimentor and it can be controlled by taking two or three readings repeatedly.

Random errors:

This errors were occurr randomly and cause of these errors is unknown.

This errors may occur by certain human error or by getting disturbance in the instrument.

Tags: ICS, Instrumentation, control system, error, errors

Benefits of CAD

Benefits of CAD:

1. Accurate results,
2. More productivity,
3. Reduces manufacturing Lead time,
4. Reduces workers,
5. Multi processing,
6. Reduce floor space,
7. Easy to modify refine and analysis the component,
8. Reduce cost,
9. Reduce scrap,
10. Easy to find a errors.

Applications of Computer for Design (Cad/Cam)

Applications of computers:

• Geometric modelling,
• Engineering analysis,
• Design review and evolution,
• Drafting.

(a)Geometric modelling:

Hear CAD package is used, which takes input from the designer as a mathematical expressions and it represents as a graphics on the interactive Computer Graphics (display).

A CAD package should capable to representing the given input as a picture on the screen.

Various packages represents the given command in different views such as wire framing representation, surface representation and volume representation.

Based on the application which method is required can be selected.,

Example: for mass  property calculations- volume representation can be used and for area calculations- surface representation can be used.

There aare continuous interaction between ICG and input devices through programmer and designer interaction.

(b) Engineering analysis:

Engineering analysis is made in two methods. mass property calculations and finite element methods

Mass property calculations: volume represented components can be used to find volume, density and cost associated with the component.

Where is finite element analysis is used to divide a component into finnet atoms into finite elements. The solution to each element is found and overall behaviour of component is determined using Global mattresses.

(c) Design review and evolution:

Once engineering analysis is done, the evolution of the component plays very important role to find out any error.

So many methods are available to review the components such as zoom in and zoom out, layering technique, colouring technique.

(d) Drafting:

Here hard copy of the component with different views such as orthogonal, isometric, oblique, 3D, 2D etc., using printers, drafters.

Tags: autocad, cad, cam, cad/cam

Design Process (CAD/CAM)

DESIGN Process:

Recognization of need:

The importance of the step is to find out problems either in existing machine or for development of new machine.

Here, the problem (or) an activity which requires much human effort is input to development of a new design.

Definition of problem:

Here the problem is represented as engineering drawing which contains clear idea about the product and its specifications. The problem is represented as 2D 3D diagrams and some simulating diagrams can be formed.

Synthesis:

Synthesis and Optimisation steps are more similar where optimal solution is developed by using engineering analysis such as mass property calculations and finite element method.

Here the product is visualised under various boundary conditions. Once this step is completed, it is followed by evaluation process where product is seen from various views to make sure there are no problems.

Presentation:

Here the design is taken in the the form of hard copy such as 2D and 3D diagrams in different views.

Tags: Cad, cam, design methods, recognisation,

Automation (CAD/CAM)

Automation:

Automation is a technology concerned with with mechanical elements, electronics and electrical in combination to perform a specific work.

The word automation means self working machines.

Automation = automatic + machine

Tags: cad, cam