Humboldt Mfg. Co., located in the United States, is a leading manufacturer and supplier of construction materials testing equipment. Our equipment is used extensively throughout the world for testing soil, concrete, cement, asphalt and aggregate in construction projects. These projects include roads; bridges; dams; earthworks, and buildings. Humboldt is known for manufacturing high-quality, competitively-priced equipment designed to comply with ASTM and AASHTO testing standards, especially our geotechnical testing equipment, our nuclear gauge and the nuclear-free, electrical density gauge.