A sensor unit comprises a mounting base (1) on which an air moisture sensor (3) and an air temperature sensor (4) are disposed. The air moisture sensor (3) is disposed over a bore (5) of the mounting base and covers the bore (5) at least partially. An intensive thermal coupling between the air moisture sensor (3), air temperature sensor (4) and air mixture to be analysed is produced.

A device for measuring moisture is described. This device includes a sensor unit (1) having a moisture-sensitive sensor element (1.1) and a carrier element (2), upon which the sensor unit is mounted. The carrier element (2), as well as the sensor unit (1) have electrical contact regions (1.2a, 1.2b). Carrier element (2) has a recess (6), above which the sensor unit (1) is mounted. The moisture-sensitive sensor element (1.1) is oriented in the direction of the recess (6). The sensor-side contact regions are formed on the side of the sensor unit (1) facing the carrier element (2). In at least one partial region adjacent to the sensor unit (1), the carrier element (2) is provided with a coating (3) which absorbs and/or releases as little moisture as possible.

An improved process for determining the presence of water in a material is disclosed. A set of electrodes is placed on the surface of a layer of the material being monitored, and an electric field is established therebetween. The phase angle for the electric field at a pre-selected frequency is measured, and compared with a predetermined phase angle for a dry portion of the material. A significant difference between the phase angle for the material being monitored and the predetermined phase angle is indicative of the presence of water in the material. The material being monitored may be an electrical insulating material, e.g., for conductive components in water-cooled electrical generators. Electrical generators monitored in this manner are also within the scope of this disclosure.

A system for the detection of the presence of undesirable moisture and drops or droplets of liquid effusing from piping systems at the first stage of appearance, comprising a low-battery alert, provision for the device to remain operative for at least 48 hours before the battery power is depleted, and sensitivity such that the presence of any unwarranted source of humidity will activate the alarm, including moisture from the proximity of the sweat of humans and from unwarranted pipe sweating (such as the cumulative effect thereof may cause water damage) will activate the alarm, alert the operator of the system to the onset of the problem, save energy, water, pumps, boilers, pipes and property, from intrusion and damage, and allow for the restoration of plumbing systems in a minimum of time. The versatility, simplicity in operating, and miniaturization of the system is such that the device may be placed in multiple, remote areas of complex piping that confound access to a larger-sized system. The monitoring device could be adapted by transmitting said alarm to a control panel such as for a large factory or residential institution, alerting the owner promptly to the location of the leak by unwarranted moisture.

A stray field electrode (1) includes a base material (2) and a conductive filler material (3). The base material is preferably an insulating material, such as a silicone elastomer film. The conductive filler material is preferably a metal, such as silver particles dispersed in the silicone elastomer film. A set of stray field electrodes (16, 17, 18) may be used to determine the presence of water in a material (8), such as electrical generator insulation (14), by comparing a phase angle for the electric field (19, 20) between the electrodes with a predetermined phase angle for a dry material (8).