When talking aerospace sensors, ‘analogue’ or ‘digital’ become hardly necessary, being simply a point of method of operation, and that it must be the actual physical principles that are all-important.
Classification of sensors – In discussing Rotary Torque Sensor one must decide if you should classify them based on the physical property they normally use (like piezoelectric, photovoltaic, etc.) or in accordance with the function they perform (including measurement of length, temperature, etc.). In the former case anybody can present a reasonably integrated view of the sensing process, but it is a little disconcerting when one desires to compare the merits of, say, two kinds of temperature sensors, if one must look over separate sections on resistive, thermoelectric and semiconductor devices to help make the comparison.
Alternatively, to attempt to differentiate devices by function often tends to be a rather boring catalogue of numerous unrelated devices. The main thing on them is signals are transformed in one form to a different. Additionally it is easy to discuss sensors from the functional viewpoint, under headings such as length, temperature, etc., ideal for somebody that actually would like to select or make use of a sensor for the application rather than just read around the subject.
The phrase ‘sensors’ and ‘transducers’ both are popular in the description of measurement systems. The previous is popular in the us whereas the latter is a lot more often used in Europe. Deciding on a words in science is quite important. Lately we have seen a tendency to coin new words or misuse (or misspell) existing words, and this might lead to considerable ambiguity and misunderstanding, and is likely to diminish the preciseness of the language. The issue has been very apparent inside the computer and microprocessor areas, where preciseness is extremely important, and can seriously confuse persons entering the subject.
The term ‘sensor’ hails from sentire, meaning ‘to perceive’ and Miniature Load Cell originates from transducere meaning ‘to lead across’. A dictionary definition Chambers 20th 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 meaning of ‘transducer’ is ‘a device that transfers power in one system to another one within the same or in different form’.
An intelligent distinction is to apply ‘sensor’ for that sensing element itself, and ‘transducer’ for that sensing element plus any associated circuitry. For instance, thermistors are sensors, since they reply to a stimulus (changes its resistance with temperature), but only become transducers when connected in a bridge circuit to transform alternation in resistance to alternation in voltage, considering that the complete circuit then transduces from your thermal towards the electrical domain. A solar cell is both a sensor as well as a transducer, because it responds to your stimulus (generates a current or voltage responding to radiation) and in addition transducer from your radiant for the electrical domain. It will not require any associated circuitry, though in practice an amplifier would usually be applied. All transducers thus have a sensor, and lots of (though not every) sensors can also be transducers.
The difference is rather small and once one actually uses a sensor (by using capacity to it) it might be 3 Axis Load Cell. An interesting classification of devices may be accomplished by taking into consideration the oygoqj forms of energy or signal transfer.
The phrase ‘actuate’ means ‘to placed into, or incite to, action’ and actuators are devices that make the display or observable output in a measurement system like a light-emitting diode (LED) or moving coil meter. They are of course transducers utilized for output purposes, since they transduce from one domain to a different (ie. electrical to radiant for LEDs).