When talking torque sensor, ‘analogue’ or ‘digital’ become hardly necessary, being simply a matter of approach to operation, and that it must be the actual physical principles which are all-important.
Classification of sensors
In discussing sensing devices one must decide if you should classify them according to the physical property they utilize (like piezoelectric, photovoltaic, etc.) or in accordance with the function they perform (including measurement of length, temperature, etc.). Within the former case you can present a reasonably integrated take a look at the sensing process, yet it is a bit disconcerting when one desires to compare the merits of, say, two types of temperature sensors, if one must examine separate sections on resistive, thermoelectric and semiconductor devices to make the comparison.
Alternatively, to try to differentiate devices by function often tends to be a relatively boring catalogue of numerous unrelated devices. What is important about the subject is signals are transformed from a single form to another. It is additionally possible to discuss miniature load cell from the functional viewpoint, under headings such as length, temperature, etc., appropriate for somebody that actually would like to select or make use of a sensor for the application as opposed to just read round the subject.
The words ‘sensors’ and ‘transducers’ both are commonly used within the description of measurement systems. The former is popular in the united states whereas the latter is a lot more often used in Europe. The option of words in science is pretty important. Lately 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 tends to diminish the preciseness in the language. The challenge has been very apparent inside the computer and microprocessor areas, where preciseness is extremely important, and can seriously confuse persons entering the niche.
The phrase ‘sensor’ is derived from sentire, meaning ‘to perceive’ and ‘transducer’ comes 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 concept of ‘transducer’ is ‘a device that transfers power from one system to a different within the same or perhaps in different form’.
An intelligent distinction is to apply ‘sensor’ for your sensing element itself, and ‘transducer’ for that sensing element plus any associated circuitry. For instance, thermistors are sensors, since they reply to a stimulus (changes its resistance with temperature), but only become transducers when connected in a bridge circuit to convert improvement in resistance to alternation in voltage, considering that the complete circuit then transduces from the thermal towards the electrical domain. A solar cell is both a sensor as well as a transducer, since it responds to your stimulus (generates a current or voltage responding to radiation) and also transducer from your radiant to the electrical domain. It can not require any associated circuitry, though in practice an amplifier would usually be used. All transducers thus hkjrzk a sensor, and lots of (though not all) sensors will also be transducers.
The distinction is pretty small, and as soon as one actually uses a sensor (by making use of capability to it) it becomes weight sensor. An interesting classification of devices can be accomplished by taking into consideration the various forms 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 for instance a light-emitting diode (LED) or moving coil meter. These are needless to say transducers employed for output purposes, given that they transduce from a single domain to another one (ie. electrical to radiant for LEDs).