Extech HD500-NIST Psychrometer & InfraRed Thermometer, 30:1, Humidity Type K w/NIST Calibration Pump PSI_500 PSI Q: How often does the

Q: How often does the pre-filter clean itself

A: The dual motor design separates suction and brush functions

heavy-duty paper to effectively trap dust

Balanced Cleaning System

Q: What type of power supply does it require

Extech HD500-NIST Psychrometer & InfraRed Thermometer, 30:1, Humidity Type K w/NIST Calibration Pump PSI_500 PSI Q: How often does theThe Extech HD500 NIST is a rugged, professional grade environmental meter that provides accurate, reliable measurements of temperature, humidity, air velocity, light intensity, and sound level. Designed for durability and ease of use, this handheld device is perfect for professionals in fields such as HVAC, building maintenance, industrial safety, and laboratory analysis. Equipped with built in sensors and a triple backlit LCD, the HD500 displays all