When talking aerospace sensors, ‘analogue’ or ‘digital’ become hardly necessary, being simply a matter of method of operation, and that it is the underlying physical principles that are all-important.
Classification of sensors – In discussing Torque Sensor one has to decide if you should classify them in accordance with the physical property they utilize (like piezoelectric, photovoltaic, etc.) or according to the function they perform (including measurement of length, temperature, etc.). Within the former case you can present a reasonably integrated view of the sensing process, however it is just a little disconcerting when one desires to compare the merits of, say, 2 kinds of temperature sensors, if one has to examine separate sections on resistive, thermoelectric and semiconductor devices to make the comparison.
Alternatively, to try to differentiate devices by function often is commonly an extremely boring catalogue of numerous unrelated devices. The important thing on them is signals are transformed in one form to another. Additionally it is possible to discuss sensors from your functional viewpoint, under headings such as length, temperature, etc., appropriate for somebody who actually wants to select or use a sensor for the application rather than just read around the subject.
The words ‘sensors’ and ‘transducers’ are both widely used within the description of measurement systems. The previous is popular in the USA whereas the latter is more often found in Europe. Deciding on a words in science is quite important. Lately there has been a propensity to coin new words or even to misuse (or misspell) existing words, and this can lead to considerable ambiguity and misunderstanding, and tends to diminish the preciseness of the language. The challenge continues to be very apparent inside the computer and microprocessor areas, where preciseness is particularly important, and can seriously confuse persons entering the niche.
The word ‘sensor’ hails from sentire, meaning ‘to perceive’ and Compression Load Cell is from transducere meaning ‘to lead across’. A dictionary definition Chambers Twentieth Century) of ‘sensor’ is ‘a device that detects a change in a physical stimulus and turns it right into a signal which may be measured or recorded’; a corresponding definition of ‘transducer’ is ‘a device that transfers power in one system to a different inside the same or even in different form’.
An intelligent distinction is to use ‘sensor’ for the sensing element itself, and ‘transducer’ for that sensing element plus any associated circuitry. As an example, thermistors are sensors, given that they react to a stimulus (changes its resistance with temperature), but only become transducers when connected in a bridge circuit to convert change in potential to deal with alternation in voltage, since the complete circuit then transduces from the thermal for the electrical domain. A solar cell is both a sensor and a transducer, since it responds to your stimulus (produces a current or voltage in reaction to radiation) as well as transducer from your radiant for the electrical domain. It can not require any associated circuitry, though in reality an amplifier would usually be used. All transducers thus contain a sensor, and many (though its not all) sensors will also be transducers.
The distinction is pretty small, and as soon as one actually utilizes a sensor (by using capacity to it) it might be Triaxial Load Cell. An interesting classification of devices can be achieved by thinking about the oygoqj types of energy or signal transfer.
The term ‘actuate’ means ‘to put 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 may be needless to say transducers utilized for output purposes, given that they transduce from one domain to another one (ie. electrical to radiant for LEDs).