Temperature sensor

Temperature sensors in PV monitoring systems measure either the module surface temperature or the ambient air temperature. A module sensor is fixed to the back of a module at the centre of a cell, in the middle of the array table and away from the array edge and frame, using a stable, thermally conductive glue. For module temperature, a sensor with an accuracy better than ±1 °C is recommended, and the adhesive should be rated for up to 83°C. Ambient sensors go outdoors in a north-facing spot that is always shaded, pointing down, inside a UV-resistant shield that allows air to circulate. Module temperature data is used to track the array's equivalent thermal resistance, which shows how well the installation is ventilated. A temperature sensor fault, such as a sensor that has come loose from the module, can show up as irregular thermal behaviour in monitoring data. Shading on the module that carries the sensor can also lower the apparent thermal resistance.