Topic 3.7 Detection, information transfer and analysis (90 GLH)

Scientists use a wide range of devices for detection and analysis. Each of these devices has a particular function and works best in a given situation. Such devices rely on the application of key scientific principles and it is important that learners understand these principles. This understanding helps learners to assess the usefulness of a device in a particular context. Only by understanding the scientific principles that underpin how a device works, and the related strengths and limitations of the device, can learners make judgements about the quality of data collected.

Scientific devices are used and developed by those working in industrial laboratories and university research departments. They are used by environmental and health scientists, geoscientists, medical physicists, analytical and forensic scientists and scientific service providers. For example public analysts use flame and atomic absorption spectrophotometers to carry out trace element analyses in occupational and environmental samples, including workplace monitoring and the detection of air pollution and water pollution.

The purpose of this topic is for learners to apply their knowledge to make and test electrical and electronic devices for detection and analysis. In order to do so learners must understand the scientific principles involved in detection by a device and the transfer of information within the device. Information transfer will usually also involve transformation into a form that can be analysed. Learners will understand the nature of electrical conduction and the use of the electromagnetic spectrum in transferring and analysing information. They will also understand the purpose of electrical components incorporated in devices for detection, information transfer and analysis. In making and testing devices, learners will justify choices made and also compare and contrast the performance of their devices to commercially available products. They will also assess the cost and suitability of their device compared to those used in industry. Learners will understand the situations in which such devices are used, and how they function and are powered.

This topic could provide an opportunity for learners to work in teams.

Learners must know and understand:

1. situations in which detection, transfer of information and analysis is required

2. principles, applications and limitations of electrical measurements for the purpose of detection or analysis

3. modelling electrical systems using mathematical equations

4. the nature and properties of the electromagnetic spectrum, including wave properties and the relationship between wavelength, frequency and energy (λ = c/ν and E = hν)

5. the role and purpose of sensors, transducers and actuators

6. the principles and applications of imaging techniques, including diffraction, wavelength and resolution

7. low and high resolution mass spectrometry principles and applications, including fragmentation patterns and parent ions

8. spectroscopic principles and analytical applications, including quantisation of energy and photon energy

9. limitations of imaging techniques, mass spectrometry and spectroscopy

10. factors influencing the quality of the information detected and analysed

11. the role and purpose of a transmitter, the transmission medium and a receiver in an information transfer system

12. how information is transferred via optical fibres, radio waves and microwaves including the use of photons, total internal reflection, critical angle, bandwidth, attenuation and polarisation

13. applications, performance characteristics and limitations of information transfer systems.

Learners must be able to:

1. design and make an electronic/electrical device for a specific detection and/or analysis purpose

2. justify scientific design features of the device to a specified audience

3. measure and analyse performance characteristics of electrical/electronic devices

4. assess capabilities, limitations and potential applications of such devices

In order to engage with this topic effectively, learners must use the following PLTS:

• reflective learners
• self managers.