When talking torque sensor, ‘analogue’ or ‘digital’ become hardly essential, being simply a matter of approach to operation, and that it is the underlying physical principles that 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 normally use (including piezoelectric, photovoltaic, etc.) or based on the function they perform (such as measurement of length, temperature, etc.). In the former case one can present a reasonably integrated take a look at the sensing process, yet it is a little disconcerting when one desires to compare the merits of, say, two types of temperature sensors, if one must look through separate sections on resistive, thermoelectric and semiconductor devices to create the comparison.
Alternatively, to attempt to differentiate devices by function often tends to be a relatively boring catalogue of numerous unrelated devices. The main thing about them is signals are transformed in one form to a different. It is additionally possible to discuss compression load cell through the functional viewpoint, under headings such as length, temperature, etc., suitable for someone who actually wants to select or utilize a sensor for the application rather than just read around the subject.
The words ‘sensors’ and ‘transducers’ both are commonly used within the description of measurement systems. The former is popular in the USA whereas the latter is more often utilized in Europe. The option of words in science is pretty important. Lately there has been an inclination to coin new words or misuse (or misspell) existing words, and this may lead to considerable ambiguity and misunderstanding, and tends to diminish the preciseness of the language. The matter continues to be very apparent in the computer and microprocessor areas, where preciseness is particularly important, and may seriously confuse persons entering the subject.
The term ‘sensor’ comes 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 change in a physical stimulus and turns it right into a signal which may be measured or recorded’; a corresponding meaning of ‘transducer’ is ‘a device that transfers power in one system to another in the same or perhaps in different form’.
A smart distinction is by using ‘sensor’ for your sensing element itself, and ‘transducer’ for the sensing element plus any associated circuitry. For example, thermistors are sensors, given that they reply to a stimulus (changes its resistance with temperature), but only become transducers when connected in a bridge circuit to convert improvement in potential to deal with change in voltage, considering that the complete circuit then transduces from your thermal for the electrical domain. A solar cell is both a sensor as well as a transducer, because it responds to some stimulus (produces a current or voltage in response to radiation) and also transducer through the radiant towards the electrical domain. It does not require any associated circuitry, though in practice an amplifier would usually be used. All transducers thus hkjrzk a sensor, and lots of (though its not all) sensors are also transducers.
The difference is rather small, and as soon as one actually works with a sensor (by making use of capability to it) it becomes load sensor. A fascinating classification of devices may be accomplished by considering the various forms of energy or signal transfer.
The word ‘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 of course transducers used for output purposes, because they transduce in one domain to another (ie. electrical to radiant for LEDs).