Humidity meter measuring water content of soil or sand - uses four specific heat transducers connected in parallel to electronic indicator unit

摘要

The probe has a baseplate (6) with four 'bedding in' legs (7). A threaded rod through the centre of the plate carries a handle (9) on its upper end and a sensor support plate (2) on its lower end. Set into the support plate are four separate detectors (2A to 2D) secured by lock nuts (3). The four probes are connected in parallel and linked (4) to a humidity detector unit (5) with a built in calculator. The probes which are of the specific heat type each contain two resistive heating elements in series with two thermocouple elements.