Surface temperature indicates the temperature of the surface of an element or object. It can be measured by contact or by infrared probes. It is important to avoid the environmental temperature in order to guarantee the measurement of the parameter using high sensibility sensors in the contact zone with the surface measure.
Based on a specific net radiometer for measuring the radiant asymmetry, we can measure the thermal radiation emitted by a body from the difference between the temperatures of the two faces of the probe. When the probe is built according to conformity ISO 7726, we can use it when measuring thermal sensation and homogeneity of an environment according to estimates by the ISO7730 standard.
Applied according to ISO 7726 standard, black balloon probes are black metallic globe in which the temperature of the indoor environment in the centre is measured. This temperature varies depending on the thermal absorption of black balloon, through this measure we can know the radiant load in an environment. Black balloon temperature is essential to perform an environmental analysis, for calculating the operating temperature and specifically for parameters PMV, PPD, WBGT SR.
According to ISO 7726, corresponds to the temperature measured in a sensor whose surface is permanently wet and has a protection to direct radiation. Wet bulb temperature is essential to perform an environmental analysis and for the calculation of WBGT according to rule ISO 7243 and UNI 9505.
The psychometric probe according to ISO 7726 has a dry bulb (direct to environment) and a wet one (permanently wet). Both probes are located in the centre of a controlled air flow (ventilation) and offer you the parameters of dry bulb temperature and wet bulb temperature (both ventilated). These two parameters allow us to calculate with good accuracy the relative humidity and all derived parameters such as absolute humidity, dew point and enthalpy of the air.
