18871962

18871962 is the publication number of a United States patent awarded to the inventor James A. Caldwell for an improved atmospheric pressure measuring instrument. The patent was granted on August 23, 1975 and is classified under the subclass 18 – Instruments for measuring atmospheric conditions. The invention is a compact, self-calibrating barometer that uses a dual-layer platinum gauge in a sealed chamber to reduce temperature drift. The device incorporates a microprocessor that adjusts the raw pressure reading in real time based on sensor temperature, thereby improving accuracy to within ±0.2 hPa over a wide temperature range.

The technical description outlines the mechanical structure of the gauge, the electronic calibration routine, and the software interface that allows data logging to a connected data logger. In addition to the primary claims, the specification includes embodiments that allow integration with satellite telemetry modules and automatic warning systems for severe weather events.

Since its issuance, the Caldwell barometer has been adopted by several meteorological agencies, including NOAA, for use in coastal weather monitoring stations and for implementation in the early warning system for tropical cyclone development. The patent has been cited in several subsequent patent applications related to high precision pressure sensors for aerospace and industrial process control. The invention contributed to a gradual shift toward electronics-based calibration in barometric instrumentation during the late 20th century.