Question 564General Subjects - Assistant Engineer70% to pass
For an analog electronic transmission system for instrumentation and control purposes, what is a common industry standard for electronic signal current range?
AI Explanation
The correct answer is C) 4 to 20mA.
The 4 to 20mA current loop is an industry standard for analog electronic signals in instrumentation and control applications. This standard is widely used because it provides a robust and reliable signal transmission method that is less susceptible to noise and interference compared to voltage-based signals. The 4mA lower limit ensures that a zero signal can be differentiated from a broken or disconnected circuit, while the 20mA upper limit provides sufficient signal range for most measurement and control applications.
The other options are incorrect because 0 to 10mA (A) is not a common industry standard, and 1 to 10A (B) and 4 to 20A (D) represent much higher current ranges that are not typical for instrumentation and control signals.
Related Questions
#562 For a pneumatic transmission system for instrumentation purposes, if a pneumatic instantaneous flow indicator has a calibrated scale of 0 to 1000 gpm, what would be the actual measured instantaneous flow rate if the transmitted pneumatic signal pressure to the indicator is 9 psig, assuming the industry standard of 3 to 15 psig is used for instrument air? #563 What type of flow measuring device would measure totalized flow volume as opposed to an instantaneous flow rate? #565 For a pneumatic transmission system for instrumentation and control purposes, what is a common industry standard for pneumatic signal pressure range? #566 Vibration characteristics to establish a baseline signature or to check the mechanical condition of machinery are measured under which of the following operative conditions? #567 A reading taken with a portable hand-held vibration meter is capable of indicating which of the following conditions?