Abstract: The invention relates to, in a sensor comprising: an electrically conductive metal housing, said housing having an inside wall forming a transmission matrix cavity, said wall having perforations therethrough; a liner transmissible of water lining said inside wall and covering said perforations; a transmission matrix filling said liner; a tablet of slowly dissolving material atop said transmission matrix; a cap closing said housing forming an electrode matrix chamber; an electrode chamber matrix in said electrode matrix chamber; a pair of spaced-apart electrodes in said electrode matrix chamber in contact with said electrode chamber matrix; the cap passing electrical leads from said electrodes; an improvement comprising said liner comprising a layer of laid, thermally bonded fibers in a pattern such as to provide-passages of such size as to confine said transmission matrix but to permit flow of moisture to and from said transmission matrix and soil in contact with it.

Abstract: An attachment for an instrument having a rotary shaft whose position is indicative of a value being measured. A needle is attached to the shaft with an inherent magnetic field, or which carries a magnet. A sensor responsive to the direction of the field is supported above the needle, and reads out the angle of the needle relative to the sensor. These readings can be used for monitoring and control purposes.

Abstract: A soil moisture sensor to be implanted in soil. The sensor has a conductive metal housing, perforated to pass moisture to and through a filter liner which lines an internal cavity. A transfer matrix is confined in the liner and is abutted by a buffer tablet of compacted gypsum. An electrode matrix abuts the tablet and bridges a pair of spaced-apart electrodes. Water, or absence of water, in the electrode matrix provides a measure of moisture in the soil as a function of electrical conductivity between the electrodes.

Abstract: A suction pump which includes a valving member including a one way check valve, a cylinder and sliding cup seal connected to said check valve so that a negative pressure can be developed by the pump. The valving member includes a valving seat, a valving ball, and a plurality of biasing leaflets. The valving body less the ball is preferably formed as an integral elastomeric body. The seal makes a sliding seal in the direction of evacuating movement, and deflects to permit air to by-pass it in the other direction.