An assembly for regulating the temperature and/or the air humidity in structures provided with an air conditioning facility and closed or closable with respect to their environment, such as switch cabinets, control installations, machine controls, electrical terminal boxes, mobile radio stations and similar enclosed facilities, wherein the assembly consists of a multi-part housing (1; 2) having a plurality of recesses or ventilation slots, wherein inside the housing (1; 2), a wiring carrier for receiving electronic components together with connecting terminals for the air conditioning facility is provided, and furthermore having an operating element for defining temperature and/or air humidity target values, wherein on the wiring carrier, a first sensor for detecting the relative ambient air humidity, a second sensor for detecting the temperature of the ambient air flowing into the housing (1; 2), as well as a third sensor for directly or indirectly detecting the heat loss of the electronic components are provided, characterized in that the wiring carrier has a plug or connector unit for connecting an external temperature sensor, wherein an access to the plug and connector unit is given via a breakthrough in the housing, the breakthrough being closed by means of a cap or a cover in the closed state, after the cover or the cap having been removed, a centring ring is fixed in the breakthrough so that a plug or a coupling connector is securely introduced, wherein the plug or the coupling connector leads to the external temperature sensor via a cable connection, wherein the centring ring has a funnel-like or cone-like inner shape, wherein a micro-controller is provided on the wiring carrier and detects at least the measured temperature values of the second and third sensor (9; 10) in a program-controlled way and predictively determines the real ambient temperature under consideration of the heat loss, and determines a correction factor from this for triggering the regulation. on the wiring carrier, a first sensor for detecting the relative ambient air humidity, a second sensor for detecting the temperature of the ambient air flowing into the housing (1; 2), as well as a third sensor for directly or indirectly detecting the heat loss of the electronic components are provided, characterized in that the wiring carrier has a plug or connector unit for connecting an external temperature sensor, wherein an access to the plug and connector unit is given via a breakthrough in the housing, the breakthrough being closed by means of a cap or a cover in the closed state, after the cover or the cap having been removed, a centring ring is fixed in the breakthrough so that a plug or a coupling connector is securely introduced, wherein the plug or the coupling connector leads to the external temperature sensor via a cable connection, wherein the centring ring has a funnel-like or cone-like inner shape, wherein a micro-controller is provided on the wiring carrier and detects at least the measured temperature values of the second and third sensor (9; 10) in a program-controlled way and predictively determines the real ambient temperature under consideration of the heat loss, and determines a correction factor from this for triggering the regulation.