MEASUREMENT ERRORS

Question 1

Define error

Answer 1

The error on a measurement result is an estimate of how close by we think the true value lies, in relation to the measurement result.

Question 2

What are the 2 types of errors?

Answer 2

Systematic and Random

Question 3

What is a systematic error?

Answer 3

Due to an unsatisfactory experimental method or measurement system design, the readings (measurements) are all biased (systematically shifted in one direction).

Question 4

How can systematic errors be reduced?

Answer 4

Systematic errors, once recognised, can generally be reduced by improvements in procedure, and eventually eliminated. Or the instruments can be calibrated to eliminate systematic errors or biases.

Question 5

What is a random error?

Answer 5

Due to random fluctuations in the measurand or the measurement system, the readings (measurements) are scattered around a mean value (readings shifted in all directions).

Question 6

How can random errors be reduced?

Answer 6

It is often very difficult to reduce random error significantly without a drastic re-design of the measurement system.

Question 7

Give some examples of a random error

Answer 7

Fluctuations in sensitivity of a sensor, electrical noise in sensor.

Question 8

Read pages 49 - 53

Answer 8

Make some notes on this as these are mainly formulae!!