Dial and digital pressure gauges and vacuum gauges monitor pressure of liquids and gases ranging from drinking water and compressed air to petrochemical processing and challenging fluids in industrial and wastewater applications. Dial industrial pressure gauges measure low and high pressures as well as vacuum and compound ranges. Digital industrial and process pressure gauges have a digital LCD display that shows numeric readings in a number of selectable engineering pressure units. Lead-free pressure gauges are certified and safe to use in systems that have contact with drinking water. Fire apparatus gauges measure pressure in fire trucks and fire sprinkler gauges measure air, water, or in sprinkler systems. HVAC and boiler gauges measure both the temperature and water pressure in boilers. Low-pressure gauges have a bellows or a diaphragm sensor for sensitive low-pressure readings. Test pressure gauges are highly accurate and used for laboratory and inspection applications.