Mercury barometer with digital read=out - has column height measured ultrasonically with microprocessor control and compensation

摘要

The mercury barometer with automatic gravity and temperature correction and digital read-out consists of conventional mercury column barometer with analogue scale. The base of the reservoir is fitted with an ultrasonic transducer (3) so that the height of the meniscus may be determined. Temp. correction is effected by means of a platinum resistance thermometer (9). Gravity and other constants, such as height above seal-level, can be fed into the microprocessor (6) which controls the entire metering process. The digital output (11, 13) is available for driving a recorder (14) and tape punch (15). An additional analogue output is provided by a digital-analogue converter (12).