Technical Explanation for Pressure Sensors CSM_Pressure_TG_E_2_2 Introduction Sensors What Is a Pressure Sensor? A pressure sensor is a device equipped with a pressure-sensitive element that measures the pressure of a gas or a liquid against a diaphragm made of stainless steel, silicon, etc., and converts the measured value into an electrical signal as an output. (The E8 Pressure Sensors use a silicon diaphragm.) Operating Principles Semiconductor distortion gauge Control Components Protective film Semiconductor Distortion Gauge Construction • A semiconductor piezo-resistance dispersion pressure sensor has a semiconductor distortion gauge formed on the surface of the diaphragm, and it converts changes in electrical resistance into an electrical signal by means of the piezo-resistance effect that occurs when the diaphragm is distorted due to an external force (pressure). Typical model: E8F2 • A static capacitance pressure sensor has a capacitor that is formed by a static glass electrode and an opposing movable silicon electrode, and it converts changes in static capacitance that occur when the movable electrode is distorted due to an external force (pressure) into an electrical signal. Typical model: E8Y Safety Components 1. Different sensors are used for different measurement targets, such as liquids, gases, flammable substances, and corrosive substances. (The E8 Sensors are used to measure the pressure of non-flammable and non-corrosive gases.) 2. There are sensors that measure the absolute pressure and those that measure the pressure relative to atmospheric pressure or a specified pressure. For sensors that use atmospheric pressure as a reference, there are sensors that measure negative pressures and positive pressures. (The E8Y is a differential pressure sensor. The E8F2 is a gauge pressure sensor that uses atmospheric pressure as the reference.) Automation Systems S The electrical resistance of the above conductor is expressed by the following formula: R = ρ x L/S. ρ: Electrical resistivity L: Conductor length S: Conductor cross-sectional area Motion / Drives When this conductor is pulled to the right or left as shown below, the length increases and the cross-sectional area decreases. Pressure is applied. L+1 Gauge foil pattern Energy Conservation Support / Environment Measure Equipment The electrical resistance of the above conductor is expressed by the following formula: R' = ρ x (L+1)/(S−s). Accordingly, R' > R. This shows how the application of a mechanical force changes the electrical resistance. Power Supplies / In Addition Othe

Technical Explanation for Pressure Sensors Reference pressure Gauge Pressure The amount of pressure is expressed in terms of atmospheric pressure. It is referred to as "positive pressure" when it is greater than one atmosphere, and "negative pressure" when it is less than one atmosphere. Absolute Pressure This is the amount of pressure expressed in relation to an absolute vacuum. Pressure Difference (Relative Pressure) This is the amount of pressure compared to any particular pressure (the reference pressure). Negative Positive pressure ! pressure Absolute Atmospheric vacuum pressure Atmospheric...

Output Impedance 1. Measuring the Output Impedance of Voltage Output Models Figure 1 The output impedance in Equation (3) is calculated as follows: Ro = Rx (■ - ) (4) The output impedance (Ro) in Equation (1) is calculated as follows: Here, the current (Io) is measured with the output short-circuited. Figure 2 The voltage (Eo) is measured when the output is open, followed by the voltage (Ex) when a load resistance (for example, the minimum value of the permitted load resistance of a transducer) is connected. The measured values Eo and Ex and the connected load resistance (Rx) are inserted into...