An apparatus and a method for measuring an altitude of a terminal which can correct an altitude error according to temporal and spatial changes are provided. The apparatus includes an atmospheric pressure measuring unit for measuring an atmospheric pressure from a barometer included in the terminal, a position determiner for measuring position information of the terminal, and a controller for, when a reference atmospheric pressure reception period is not generated, predicting a current reference atmospheric pressure by using previously received reference atmospheric pressures and measuring a current altitude by using the predicted reference atmospheric pressure and the measured atmospheric pressure.

A sensor arrangement having: a first sensor cell which can be excited thermally by means of a heater; a second sensor cell which can be excited thermally by means of a heater; and an evaluation; wherein the first and second sensor cells are sensor cells of the same kind and are dimensioned and/or configured differently, and are configured to form a respective oscillation behavior in dependence on a gas property of a gas surrounding the sensor cells, in particular heat conductivity, volume heat capacity, temperature and/or pressure, and the evaluation is configured to evaluate the oscillation behavior of the first and second sensor cells together in order to determine the heat conductivity and volume heat capacity, heat conductivity being determined based on the oscillation behavior of the first sensor cell and volume heat capacity being determined based on the oscillation behavior of the second sensor cell.

A measurement system is configured to determine a pressure of a liquid of interest having compressibility k.sub.m flowing in a channel of radius r.sub.int, which are selected such that the product k.sub.mr.sub.int is less than or equal to 12.510.sup.11 mm/Pa. The system includes a flow actuator for flowing the liquid of interest in the channel at a Mach number less than or equal to 0.3, a thermal measurement device for measuring a temperature of the liquid of interest flowing in the channel, and a processing unit configured to determine the pressure from the temperature measured and a predetermined calibration function.

Provided is a sensor device disposed in a semiconductor manufacturing apparatus, the sensor device including a sensor array configured to be in a flow path of a gas supplied to the semiconductor manufacturing apparatus, the sensor array including a first calorimeter and a second calorimeter, and a controller configured to identify a pressure of the gas based on a temperature of the first calorimeter, an ambient temperature, and a first amount of heat transfer in the first calorimeter, and identify a flow velocity of the gas based on a temperature of the second calorimeter, the ambient temperature, a second amount of heat transfer in the second calorimeter, and the pressure.