McCullough Geotechnical Gauge

Product Code: 77325

The McCullough Geotechnical Gauge is a compact, waterproof field reference designed to help geologists, geotechnical engineers, environmental scientists, archaeologists, and soil technicians make accurate and consistent soil classifications in the field. Printed on a durable, flexible plastic card, it combines numerous essential soil identification references into a single easy-to-carry tool, allowing rapid field assessments without the need for bulky manuals or charts. It has become a widely recognised reference for geotechnical investigations, environmental site assessments, archaeological excavations, and educational fieldwork.

The gauge incorporates a centimetre and inch ruler, grain roundness chart, percentage composition chart, six common Munsell® soil colour references, the Unified Soil Classification System (USCS), soil compaction guidance for sands and clays, and a unique grain-size comparison scale using actual sand grains permanently fused to the card. Measuring 5 × 7 in. (127 × 178 mm) and supplied with a nylon lanyard, the waterproof card is designed for years of reliable use in all weather conditions.