Sensors photoelectric devices

The sensor for each pixel in a digital camera is a tiny photoelectric device. The photoelectric sensors that open some snpermarket and elevator doors also utilize this effect. 

Photosensors. These are the most commonly used sensing and scanning devices. A photoelectric control consists of a light source, photoreceiver, amplifier, and output. A beam of light from the hght source activates the photosensitive elements of the photoreceiver which produces an electric signal, which drives a relay to activate the diverting mechanism. When used as a sensor, photoelectric controls can be used to ... 

Fuel cell polymer battery photoelectric cell capacitor Storage element liquid crystal display device electrochromic display device electrochemiluminescence device photoelectric transducer Biosensor ion sensor detector in HPLC and FIA gas sensor voltam-metric indicator electrode reference electrode... 

Photoelectric Beam Another type of presencesensing device uses light beams and photoelectric sensors (Figure 13-12). An array of beams forms a horizontal, vertical, or combined pattern. If someone inserts something into the array and it interrupts one or more of the beams, the machine stops or will not operate. Because the array is not easily seen, one must depend on a display to know if it is functioning correctly. 

In some types of photoelectric detectors, a vacuum pump draws air liom one or more locations to a central sensing device. Any of the sources can trigger a response from the sensor. 

Fluorescent and photoluminescent nanofiUers, such as CdTe, CdSe, CdS nanoparticles or quantum dots (QDs), ZnS and ZnSe QDs, and complexes of trivalent europium ion (Eu ), are promising inorganic materials with photoelectric, thermoelectric, and photoluminescent properties that find applications in optoelectronic devices, optical sensors, as photocatalysts for organic pollutants remediation [39] or hydrogen production [40], and as fluorescent biomaterials [41]. 

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