{"id":154,"date":"2021-01-31T23:32:11","date_gmt":"2021-01-31T23:32:11","guid":{"rendered":"http:\/\/learnlearn.uk\/igcsecs\/?page_id=154"},"modified":"2022-01-25T08:54:11","modified_gmt":"2022-01-25T08:54:11","slug":"sensors","status":"publish","type":"page","link":"https:\/\/learnlearn.uk\/igcsecs\/sensors\/","title":{"rendered":"Sensors"},"content":{"rendered":"
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Sensors<\/h2>\n
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Introduction to sensors<\/h3>\n

Sensors are everywhere, though we rarely even notice them. Take you mobile phone – how many sensors can you thing of that it has?*<\/p>\n

Their job is to alter the electrical signal that is passed through them depending on the value that they are sensing.<\/p>\n

For example for a simple Light dependent Resistor (LDR) the resistance within the resistor varies depending on the amount light hitting the surface of the resistor.<\/p>\n

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LDR Resitance falls with increased light on the sensor. Source Wikipedia<\/p><\/div>\n

Digital versus analogue sensors<\/strong><\/p>\n

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Digital accelerometer<\/p><\/div>\n

Simple sensors like the LDR above are analogue sensors. They simply emit a raw analogue signal. This means that the signal has to converted to digital using an analogue to digital converter (ADC)\u00a0<\/strong>before the signal can be used.<\/p>\n

More advanced sensors had a built in microchip that has an in-built ADC that converts the signal to digital before sending the digital signal on to the controlling device. Digital sensors are usually more accurate and reliable, but are more complex and expensive.<\/p>\n

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*I can think of 7, can you beat me?<\/p>\n\n<\/div>

Temp<\/h2>\n
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Temperature Sensor<\/h3>\n

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Digital temperature sensor. Source: Wikipedia<\/p>\n

Temperature sensors are sensors that detect the temperature. Sometimes this is achieved through contact with the object to be measured, sometimes is it done through measure the ambient temperature of the room or environment.<\/p>\n

Contact Sensors<\/strong><\/p>\n

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Contact temperatures sensors are used when you want to measure the specific temperature of an object, not the environment it is in. A common example is a digital mouth thermometer. The end of the probe must come in contact with mouth tissues in order to get a reading.<\/p>\n

Ambient Sensor<\/strong><\/p>\n

Ambient temperatures are used to measure the temperature of the nearby environment, such as the temperature of a room. They are also used in farms to help with rearing young chicks. The incubator needs to be kept at a specific temperature in order to for the chicks to hatch.\"\"<\/p>\n

Common uses of temperature sensors<\/strong><\/p>\n