| What is a sensor? | Sensor is a device which reads and measure physical properties |
| Physical data are known as what data | Analogue data which means that they are constantly changing and dont have a constant value |
| Why do we convert analogue data to digital data? What do we use to convert it? | because computer cannot interpret analogue data. We use a Analogue to Digital Converter (ADC) |
| What is ADC used with? | An actuator which requires DAC to receive electric current |
| What is an actuator | a type of electromechanical output device used to control something |
| What is required when computers are used to control device? | A digital to analogue converter (DAC) |
| List the nine types of sensors | temperature, moisture, light, motion, pressure, sound, gas, pH, magnetic field |
| What are the two keywords in describing each sensor | monitoring and controlling |
| What are the 3 uses of temperature sensor | 1. controlling a central heating system
2. control and monitor a chemical process
3. control and monitor temperature of greenhouse |
| What are the 2 uses of moisture sensor | 1. control and monitor moisture level of soil and air in greenhouse
2. monitors dampness of industrial application |
| What is the 3 use of light sensor | control street light, headlight in car, lights in greenhouse |
| What are the three uses of motion sensor | 1. monitors intrudes in burglar alarm system
2. Control sensor doors in malls
3. Controls wind screen wipers in car |
| What are the 3 uses of pressure sensor | 1. monitor intrudes
2. control weighing system
3. control and monitor gas pressure related process |
| What are the 2 uses of sound sensor | 1. monitor intrudes
2. monitor noise of liquid dripping for pipe |
| What is the 3 use of gas sensor | 1. monitor pollution in water/air
2. monitor O2 and CO2 in green house
3. Monitor CO2 leaks in power stations |
| What is the two use of pH sensor | 1. controlling and monitoring acidity and alkalinity of soil in greenhouse
2. monitor pollution in water |
| What is the 2 use of magnetic field | 1. control anti-lock breaking system of cars
2. controlling application involve magnetic field charges (cell phone) |
| How does a sensor work? | 1. Sensor sends signal to computer
2. Signals are then converted to digital using ADC
3. Computer checks data received against store values
4. if received data is outside range of control system, control or monitor action will happen depending on the situation
5. number of minutes pass before next reading |
| After a signal is send by sensor to computer, what happens? | signals are converted into digital data using ADC |
| When signals are converted into digital data using ADC what happens? | computer checks data received against store values |
