Instruments

Comparison of flow meters 
Working and measuring methods of various flow meters

Thermocouple types 
Temperature measuring instruments comparison 

pH meter 
What is pH and to calculate pH value

Pressure gauge 
Pressure measuring instruments working methods and applications

Composition analysis
Chemical compound chemical analysis

Liquid level measurement
Level measuring techniques and devices to measure liquid level in storage tanks

Pitot tube

Fluid flow measurement

UPS