Compact & handheld equipment for calibration, measurement, & test of Air Velocity & Flow, Back Flow, Carbon Monoxide, Combustion, Distance, Electrical Control Signals, Conductivity, Electricity, Gas Detection/Analysis, Ground & Continuity, HVAC Balancing, Humidity, Light, Moisture, Open Channel Surface Flow, ORP, pH, Pipe Thickness, Pressure, Rotational Speed, Salinity, Sound, Temperature, and Wind Speed.