The instrument is an optical microscope.
It sends an electric signal to the valve to tell it to turn on or off.
Current Carries Negatively charged electrons.
The quality of a signal is a measure of how much the signal has changed during transmission. A high quality signal has changed very little. A low quality signal has other information in it which was not there in the original signal. The additional unwanted information is called noise.
A lower power lens tells its name in the name. It is a lens in a microscope that has the lowest power, or only magnifies the object you are looking at a little.
An amplifier.
amplifier
You could be getting a signal from a tracer wire.
Weak signal depending upon the type of signal.
voltmeters
Electronic signal.
A doctor
A doctor
microscope
Transformer
Detector converts optical signal to electric signal
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