A total station whose principal function is geodetic or construction surveying — measuring angles, distances, and elevations — classifies under heading 9015 even if it incorporates GNSS positioning. The navigational instruments heading applies when the primary function is determining a course or position for transport purposes. The instrument's design specification and intended use are the key classification factors.

Meteorological instruments such as barometers, hygrometers, and anemometers designed for professional atmospheric measurement fall under subheading 901580 alongside oceanographic and geophysical instruments. Consumer-grade weather gadgets may instead classify under the general measuring-instrument heading depending on their precision and intended use; consult the chapter notes or seek a binding ruling for ambiguous products.