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A thermopile is an electronic device that converts thermal energy into electrical energy. [1] It is composed of several thermocouples connected usually in series or, less commonly, in parallel . Such a device works on the principle of the thermoelectric effect , i.e., generating a voltage when its dissimilar metals (thermocouples) are exposed ...
For sporadic measurements outside the laser system (e.g. during maintenance) a separate measuring unit is beneficial. For such a power meter, the sensor element is usually integrated into a metal housing for mechanical and thermal stability. The signal is recorded and processed in a read-out unit which displays the measured laser power (Fig 8 ...
A typical optical power meter consists of a calibrated sensor, measuring amplifier and display. The sensor primarily consists of a photodiode selected for the appropriate range of wavelengths and power levels. On the display unit, the measured optical power and set wavelength is displayed. Power meters are calibrated using a traceable ...
The magnitude of the voltage depends on the types of wire being used. Generally, the voltage is in the microvolt range and care must be taken to obtain a usable measurement. Although very little current flows, power can be generated by a single thermocouple junction. Power generation using multiple thermocouples, as in a thermopile, is common.
Heat flux sensors are used for a variety of applications. Common applications are studies of building envelope thermal resistance, studies of the effect of fire and flames or laser power measurements. More exotic applications include estimation of fouling on boiler surfaces, temperature measurement of moving foil material, etc.
Measuring instruments in fiction: Captain Nemo and Professor Aronnax contemplating thermometers, barometers, clocks, etc. in Jules Verne's 1869-1870 science fiction novel Twenty Thousand Leagues Under the Seas Fun measuring instruments: a Love Meter and strength tester machine at a Framingham, Massachusetts rest stop.
Both thermopile and bolometer are passive detectors while microbolometers can also have an active structure, but the transistor used is a TFT (thin-film transistor). The main advantages of using TMOS sensor are: High sensitivity and responsivity due to the active working mode, and in particular biasing the transistor in subthreshold region.
This standard defines a table structure for utility application data to be passed between an end device and a computer. The "end device" is typically an electricity meter, and the "computer" is typically a hand-held device carried by a meter reader, or a meter communication module which is part of an automatic meter reading system. C12.19 does ...