When talking aerospace sensors, ‘analogue’ or ‘digital’ become hardly necessary, being simply a point of method of operation, and that it is the underlying physical principles that are all-important.
Classification of sensors – In discussing Torque Transducer one has to decide whether to classify them based on the physical property they use (such as piezoelectric, photovoltaic, etc.) or in accordance with the function they perform (including 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 temperature sensors, if one must examine separate sections on resistive, thermoelectric and semiconductor devices to create the comparison.
Alternatively, to attempt to differentiate devices by function often is usually a relatively boring catalogue of numerous unrelated devices. The main thing about them is signals are transformed in one form to another one. Additionally it is possible to discuss sensors through the functional viewpoint, under headings such as length, temperature, etc., ideal for somebody that actually wants to select or make use of a sensor for a particular application as opposed to just read round the subject.
The words ‘sensors’ and ‘transducers’ both are commonly used in the description of measurement systems. The first kind is popular in the united states whereas the latter is much more often used in Europe. The choice of words in science is rather important. In recent years we have seen a propensity to coin new words or misuse (or misspell) existing words, and this can lead to considerable ambiguity and misunderstanding, and has a tendency to diminish the preciseness in the language. The issue has been very apparent within the computer and microprocessor areas, where preciseness is extremely important, and can seriously confuse persons entering the topic.
The word ‘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 difference in a physical stimulus and turns it right into 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 within the same or in different form’.
A sensible distinction is by using ‘sensor’ for that 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), only become transducers when connected in a bridge circuit to transform improvement in effectiveness against change in voltage, because the complete circuit then transduces from your thermal to the electrical domain. A solar cell is both a sensor and a transducer, since it responds to a stimulus (creates a current or voltage in response to radiation) and also transducer from your radiant for the electrical domain. It does not require any associated circuitry, though in reality an amplifier would usually be used. All transducers thus include a sensor, and many (though its not all) sensors are also transducers.
The distinction is rather small, and once one actually utilizes a sensor (by making use of capability to it) it will become Multi Axis Load Cell. An interesting classification of devices can be achieved by considering the oygoqj kinds of energy or signal transfer.
The word ‘actuate’ means ‘to put in, 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. These are of course transducers employed for output purposes, given that they transduce in one domain to another (ie. electrical to radiant for LEDs).