When talking aerospace sensors, ‘analogue’ or ‘digital’ become hardly necessary, being simply a matter of way of operation, and that it is the underlying physical principles which are all-important.
Classification of sensors. In discussing sensing devices one must decide whether or not to classify them in accordance with the physical property they use (like piezoelectric, photovoltaic, etc.) or based on the function they perform (like measurement of length, temperature, etc.). In the former case you can present a reasonably integrated view of the sensing process, yet it is a bit disconcerting when one wishes to compare the merits of, say, two types of 3 Axis Load Cell, if one has to look over separate sections on resistive, thermoelectric and semiconductor devices to help make the comparison.
Alternatively, to try and differentiate devices by function often tends to be a rather boring catalogue of numerous unrelated devices. The important thing about the subject is signals are transformed in one form to another. It is also possible to discuss Rotary Torque Sensor from the functional viewpoint, under headings like length, temperature, etc., appropriate for somebody who actually desires to select or utilize a sensor for a particular application as opposed to just read across the subject.
The text ‘sensors’ and ‘transducers’ are generally commonly used inside the description of measurement systems. The former is popular in the united states whereas the second is a lot more often utilized in Europe. Deciding on a words in science is rather important. In recent years we have seen a tendency to coin new words or to misuse (or misspell) existing words, and this might lead to considerable ambiguity and misunderstanding, and tends to diminish the preciseness of the language. The matter continues to be very apparent within the computer and microprocessor areas, where preciseness is especially important, and will seriously confuse persons entering the niche.
The term ‘sensor’ comes 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 difference in a physical stimulus and turns it in to a signal which can be measured or recorded’; a corresponding definition of ‘transducer’ is ‘a device that transfers power from one system to another one in the same or perhaps in different form’.
A smart distinction is to apply ‘sensor’ for the sensing element itself, and ‘transducer’ for the sensing element plus any associated circuitry. For instance, thermistors are sensors, given that they respond to a stimulus (changes its resistance with temperature), but only become transducers when connected in a bridge circuit to transform change in resistance to improvement in voltage, because the complete circuit then transduces from your thermal towards the electrical domain. A solar cell is both a sensor as well as a transducer, since it responds to some stimulus (creates a current or voltage in reaction to radiation) and in addition transducer from your radiant to the electrical domain. It will not require any associated circuitry, though in practice an amplifier would usually be utilized. All transducers thus have a sensor, and several (though not all) sensors will also be transducers.
The difference is quite small, and as soon as one actually utilizes a sensor (by making use of capacity to it) it will become Miniature Force Sensor. A fascinating classification of devices can be achieved by thinking about the various hdjjdy of energy or signal transfer.
The phrase ‘actuate’ means ‘to put into, or incite to, action’ and actuators are devices that produce the display or observable output in a measurement system such as a light-emitting diode (LED) or moving coil meter. They may be needless to say transducers used for output purposes, since they transduce in one domain to another one (ie. electrical to radiant for LEDs).