A basic resistive pressure sensor, also known as a resistive pressure transducer, is a type of sensor used to measure pressure by converting the applied pressure into an electrical signal. The function of a basic resistive pressure sensor involves the following components and principles:
Sensing Element: The sensor contains a sensing element that deforms or changes its resistance in response to the applied pressure. Common sensing elements used in resistive pressure sensors include strain gauges, piezoresistive elements, or resistive ink.
Resistive Element: The sensing element is usually a resistive material with known electrical properties. When pressure is applied, the sensing element experiences a mechanical deformation, leading to a change in its resistance value.
Wheatstone Bridge Configuration: The resistive element is typically part of a Wheatstone bridge circuit. The Wheatstone bridge is a network of four resistors arranged in a diamond configuration. The voltage across the bridge is measured to determine the change in resistance caused by the applied pressure.
Voltage Output: As the pressure changes, the resistance of the sensing element changes accordingly. This leads to an unbalance in the Wheatstone bridge circuit, causing a change in the output voltage. The magnitude of the voltage change is proportional to the applied pressure.
Signal Conditioning: The output voltage from the Wheatstone bridge may be very small and susceptible to noise. Signal conditioning circuitry is used to amplify and filter the signal, ensuring accurate and reliable pressure measurements.
Calibration: To provide accurate pressure readings, resistive pressure sensors often require calibration. Calibration involves determining the relationship between the applied pressure and the corresponding output voltage.
Applications of basic resistive pressure sensors include various industries, such as automotive, aerospace, medical devices, HVAC (heating, ventilation, and air conditioning), and industrial automation. They are commonly used for pressure monitoring, control systems, and safety applications where a simple and cost-effective pressure measurement solution is required. However, it's essential to note that more advanced pressure sensors with different sensing principles, such as capacitive or piezoelectric sensors, are also available for specific applications that demand higher accuracy or performance.