Refractometers measure index of refraction. BRIX is a specific application for sugar concentration in a liquid solution.
Ultrasonic Leak Detectors “listen” for gas leaks in compressed air, refrigerant gas lines, steam lines, vacuum lines, and other HVAC/R applications
Hot Air Guns are used for efficient drying as well as heat-shrinking, thawing frozen pipes, heating liquids, bending materials, and more
Thermometers are temperature measuring instruments. Two main categories are contact type and infrared