Abstract: A method of monitoring radon in an area, comprising: acquiring a series of radon measurements for the area; obtaining a characteristic value relating to ventilation in the area; and calculating a weighted average from the series of radon measurements. Using a characteristic of the ventilation to calculate the weights allows some knowledge of the ventilation rate to be used in the averaging process so as to improve the quality of the averaged data. With a high ventilation rate, the radon level drops rapidly, with the removal of radon by ventilation dominating any radon source, and so an average can be more strongly weighted towards the current value. With a low ventilation rate, the removal of radon slows and so the noise in the data is taken into account. Combining the actual radon measurements with knowledge of the ventilation rate allows the averaging function to provide better time resolution.

Abstract: A method of estimating occupancy of a room, comprising: acquiring a plurality of measurements of an aspect of air quality in the room; and estimating the occupancy of the room based on the plurality of measurements and a room ventilation rate parameter. By estimating the occupancy of the room based on aspects of air quality, it is possible to detect occupancy based on data from sensors which may already be present for other purposes (e.g. for measuring air quality). Combining measurements of air quality with knowledge related to ventilation rate results in information indicative of the occupancy. Estimating the number of people in the room allows detailed analysis and control to be undertaken. Such occupancy data can also be used to control other services, e.g. to control the ventilation or to provide information about the number of people present.

Abstract: An apparatus includes an integrated circuit (IC), which includes a voltage regulator. The voltage regulator includes a first transistor coupled to an input voltage of the voltage regulator and a first output of the voltage regulator. The first transistor includes a native device of the IC. The voltage regulator further includes at least one diode-connected transistor coupled to the first output of the voltage regulator.