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A passive infrared sensor (PIR sensor) is an electronic sensor that measures infrared (IR) light radiating from objects in its field of view. They are most often used in PIR-based motion detectors. PIR sensors are commonly used in security alarms and automatic lighting applications. PIR sensors detect general movement, but do not give ...
An occupancy sensor is an indoor device used to detect the presence of a person. Applications include automatic adjustment of lights or temperature or ventilation systems in response to the quantity of people present. The sensors typically use infrared, ultrasonic, microwave, or other technology. The term encompasses devices as different as PIR ...
Piezoelectric sensor. A piezoelectric disk generates a voltage when deformed (change in shape is greatly exaggerated) A piezoelectric sensor is a device that uses the piezoelectric effect to measure changes in pressure, acceleration, temperature, strain, or force by converting them to an electrical charge. The prefix piezo- is Greek for 'press ...
Pyroelectricity. Internals of a pyroelectric sensor. Pyroelectricity (from Greek: pyr (πυρ), "fire" and electricity) is a property of certain crystals which are naturally electrically polarized and as a result contain large electric fields. [1] Pyroelectricity can be described as the ability of certain materials to generate a temporary ...
A motion detector is an electrical device that utilizes a sensor to detect nearby motion (motion detection). Such a device is often integrated as a component of a system that automatically performs a task or alerts a user of motion in an area. They form a vital component of security, automated lighting control, home control, energy efficiency ...
The generalised chemical structure of polyisocyanurate showing the isocyanurate group. The polyols are abbreviated as R-groups.. Polyisocyanurate (/ ˌ p ɒ l ɪ ˌ aɪ s oʊ s aɪ ˈ æ nj ʊər eɪ t /), also referred to as PIR, polyol, or ISO, is a thermoset plastic [1] typically produced as a foam and used as rigid thermal insulation.
A piping and instrumentation diagram (P&ID) is defined as follows: A diagram which shows the interconnection of process equipment and the instrumentation used to control the process. In the process industry, a standard set of symbols is used to prepare drawings of processes. The instrument symbols used in these drawings are generally based on ...
Current loop. In electrical signalling an analog current loop is used where a device must be monitored or controlled remotely over a pair of conductors. Only one current level can be present at any time. A major application of current loops is the industry de facto standard 4–20 mA current loop for process control applications, where they are ...