How Do Temperature Sensors Work?

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A temperature sensor measures the hotness or coolness of an object. The sensor’s working base is the voltage that’s read across the diode. The temperature rises whenever the voltage increases. The sensor records any voltage drop between the transistor base and emitter. When the difference in voltage is amplified, the device generates an analogue signal that’s proportional to the temperature.

A temperature sensor measures temperature using four measurement scales that are divided into various degree units. The measurement scales use the metric Celsius scale, and they start at zero. The Rankin scale is the absolute scale that uses Fahrenheit temperature sensing. Temperature sensors determine absolute zero measurements as close to minus 460 degrees Fahrenheit. The Rankin scale measures absolute zero as 492 degrees Rankin.

A popular thermal measuring method is thermocouple, which is composed of two different metal alloy wires. Combining two different metals generates a strong voltage that has the same capacity as temperature. Thermocouples typically provide vast measurement ranges. They work using the Seebeck effect which involves changes in temperature in electrical circuits. The sensors read temperature by taking measurements of voltage outputs.

Thermistors are another type of temperature sensor, and they’re mostly used in human thermometers and appliances. Their predictable resistance reacts to temperature change. When temperature changes, the electrical current or resistance also changes.

Non-contact temperature sensors measure temperature without touching the object. They measure thermal radiation to determine temperature.