Industrial Instrumentation - Measurement

Instrumentation is the science of automated measurement and control. Applications of this science
abound in modern research, industry, and everyday living. From automobile engine control systems
to home thermostats to aircraft autopilots to the manufacture of pharmaceutical drugs, automation
surrounds us.

The first step, naturally, is measurement. If we can’t measure something, it is really pointless to
try to control it. This “something” usually takes one of the following forms in industry:

• Fluid pressure
• Fluid flow rate
• The temperature of an object
• Fluid volume stored in a vessel
• Chemical concentration
• Machine position, motion, or acceleration
• Physical dimension(s) of an object
• Count (inventory) of objects
• Electrical voltage, current, or resistance

Once we measure the quantity we are interested in, we usually transmit a signal representing
this quantity to an indicating or computing device where either human or automated action then
takes place. If the controlling action is automated, the computer sends a signal to a final controlling
device which then influences the quantity being measured.