When talking aerospace sensors, ‘analogue’ or ‘digital’ become hardly necessary, being simply a matter of method of operation, and that it is the actual physical principles that are all-important.
Classification of sensors. In discussing sensing devices one must decide if you should classify them based on the physical property they utilize (such as piezoelectric, photovoltaic, etc.) or according to the function they perform (like measurement of length, temperature, etc.). Inside the former case one can present a reasonably integrated view of the sensing process, yet it is just a little disconcerting when one would like to compare the merits of, say, two types of Multi Axis Force Sensor, if one must examine separate sections on resistive, thermoelectric and semiconductor devices to help make the comparison.
Alternatively, to attempt to differentiate devices by function often is commonly a relatively boring catalogue of numerous unrelated devices. What is important about them is signals are transformed in one form to a different. It is additionally possible to discuss Torque Sensor through the functional viewpoint, under headings including length, temperature, etc., ideal for somebody that actually desires to select or use a sensor for the application rather than just read across the subject.
The phrase ‘sensors’ and ‘transducers’ are generally commonly used within the description of measurement systems. The first kind is popular in the us whereas the latter is a lot more often utilized in Europe. The option of words in science is rather important. Recently we have seen a tendency to coin new words or to misuse (or misspell) existing words, and this can lead to considerable ambiguity and misunderstanding, and is likely to diminish the preciseness of the language. The issue continues to be very apparent in the computer and microprocessor areas, where preciseness is particularly important, and can seriously confuse persons entering the subject.
The term ‘sensor’ is derived from sentire, meaning ‘to perceive’ and ‘transducer’ is from transducere meaning ‘to lead across’. A dictionary definition Chambers 20th Century of ‘sensor’ is ‘a device that detects a big difference in a physical stimulus and turns it right into a signal which is often measured or recorded’; a corresponding meaning of ‘transducer’ is ‘a device that transfers power from one system to another inside the same or even in different form’.
An intelligent distinction is to use ‘sensor’ for your sensing element itself, and ‘transducer’ for your sensing element plus any associated circuitry. As an example, thermistors are sensors, because they reply to a stimulus (changes its resistance with temperature), but only become transducers when connected in a bridge circuit to transform improvement in potential to deal with improvement in voltage, since the complete circuit then transduces from the thermal to the electrical domain. A solar cell is both a sensor and a transducer, since it responds to some stimulus (produces a current or voltage in reaction to radiation) as well as transducer from the radiant towards the electrical domain. It does not require any associated circuitry, though in reality an amplifier would usually be used. All transducers thus have a sensor, and lots of (though not every) sensors can also be transducers.
The difference is rather small, and as soon as one actually works with a sensor (by making use of capacity to it) it will become S Type Load Cell. A fascinating classification of devices can be accomplished by taking into consideration the various hdjjdy 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 such as a light-emitting diode (LED) or moving coil meter. They may be needless to say transducers used for output purposes, because they transduce from one domain to another one (ie. electrical to radiant for LEDs).