When talking aerospace sensors, ‘analogue’ or ‘digital’ become hardly necessary, being simply a matter of approach to operation, and that it is the actual physical principles that are all-important.
Classification of sensors. In discussing sensing devices one has to decide whether to classify them according to the physical property they utilize (like piezoelectric, photovoltaic, etc.) or in accordance with the function they perform (such as measurement of length, temperature, etc.). In the former case anybody can present a reasonably integrated view of the sensing process, but it is a bit disconcerting when one desires to compare the merits of, say, two types of Multi Axis Force Sensor, if one has to look over separate sections on resistive, thermoelectric and semiconductor devices to help make the comparison.
Alternatively, to try to differentiate devices by function often is usually a rather boring catalogue of numerous unrelated devices. What is important on them is signals are transformed in one form to another one. It is additionally easy to discuss Torque Sensor through the functional viewpoint, under headings like length, temperature, etc., ideal for somebody who actually desires to select or utilize a sensor for the application as opposed to just read round the subject.
The words ‘sensors’ and ‘transducers’ are generally popular within the description of measurement systems. The previous is popular in the USA whereas the latter is a lot more often utilized in Europe. Deciding on a words in science is rather important. In recent years we have seen an inclination to coin new words or even to misuse (or misspell) existing words, and this might lead to considerable ambiguity and misunderstanding, and has a tendency to diminish the preciseness of the language. The matter continues to be very apparent inside the computer and microprocessor areas, where preciseness is particularly important, and can seriously confuse persons entering the subject.
The term ‘sensor’ hails from sentire, meaning ‘to perceive’ and ‘transducer’ originates from transducere meaning ‘to lead across’. A dictionary definition Chambers Twentieth Century of ‘sensor’ is ‘a device that detects a big change in a physical stimulus and turns it in to a signal which is often measured or recorded’; a corresponding concept of ‘transducer’ is ‘a device that transfers power in one system to a different in the same or even in different form’.
A smart distinction is to apply ‘sensor’ for that sensing element itself, and ‘transducer’ for the sensing element plus any associated circuitry. For instance, thermistors are sensors, because they respond to a stimulus (changes its resistance with temperature), but only become transducers when connected in a bridge circuit to transform improvement in effectiveness against change in voltage, considering that the complete circuit then transduces from the thermal towards the electrical domain. A solar cell is both a sensor as well as a transducer, since it responds to your stimulus (produces a current or voltage in reaction to radiation) and in addition transducer through the radiant for the electrical domain. It does not require any associated circuitry, though in reality an amplifier would usually be utilized. All transducers thus contain a sensor, and several (though not all) sensors can also be transducers.
The distinction is pretty small and as soon as one actually uses a sensor (by using power to it) it becomes Jr S Beam Load Cell. An appealing classification of devices may be accomplished by considering the various hdjjdy of energy or signal transfer.
The phrase ‘actuate’ means ‘to put in, or incite to, action’ and actuators are devices that make the display or observable output in a measurement system for instance a light-emitting diode (LED) or moving coil meter. They are obviously transducers used for output purposes, since they transduce in one domain to a different (ie. electrical to radiant for LEDs).