When talking aerospace sensors, ‘analogue’ or ‘digital’ become hardly necessary, being simply a matter of method of operation, and that it must be 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 use (such as piezoelectric, photovoltaic, etc.) or based on the function they perform (such as measurement of length, temperature, etc.). Within the former case you can present a reasonably integrated view of the sensing process, but it is just a little disconcerting when one desires to compare the merits of, say, two types of temperature sensors, if one has to look through separate sections on resistive, thermoelectric and semiconductor devices to 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 about the subject is signals are transformed from one form to a different. It is also easy to discuss sensors through the functional viewpoint, under headings such as length, temperature, etc., ideal for somebody that actually desires to select or utilize a sensor for the application rather than just read around the subject.
The phrase ‘sensors’ and ‘transducers’ both are commonly used in the description of measurement systems. The previous is popular in the united states whereas the latter is more often found in Europe. The option of words in science is quite important. In recent years we have seen a propensity to coin new words or misuse (or misspell) existing words, and this might lead to considerable ambiguity and misunderstanding, and has a tendency to diminish the preciseness in the language. The challenge has been very apparent inside the computer and microprocessor areas, where preciseness is especially important, and can seriously confuse persons entering the subject.
The word ‘sensor’ is derived from sentire, meaning ‘to perceive’ and Compression Load Cell 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 right into a signal which can be measured or recorded’; a corresponding meaning of ‘transducer’ is ‘a device that transfers power from one system to a different inside the same or perhaps 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 respond to a stimulus (changes its resistance with temperature), only become transducers when connected in a bridge circuit to transform change in effectiveness against alternation in voltage, since the complete circuit then transduces from your 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 response to radiation) and in addition transducer from the radiant towards the electrical domain. It will not require any associated circuitry, though in practice an amplifier would usually be utilized. All transducers thus contain a sensor, and several (though not all) sensors will also be transducers.
The distinction is rather small, and as soon as one actually uses a sensor (by applying capability to it) it will become 3 Axis Load Cell. An interesting classification of devices may be accomplished by taking into consideration the oygoqj kinds of energy or signal transfer.
The phrase ‘actuate’ means ‘to placed into, or incite to, action’ and actuators are devices that produce the display or observable output in a measurement system like a light-emitting diode (LED) or moving coil meter. They may be obviously transducers utilized for output purposes, because they transduce from a single domain to another (ie. electrical to radiant for LEDs).