The GHS393 is an innovative sensor for detecting humidity in oils. Using a capacitive sensor element, it measures relative humidity or water activity, as well as the current medium temperature via a digital temperature sensor. Based on these two measurements, the absolute moisture concentration can be calculated if the oil’s saturation curve is known. This combination is ideal for applications such as aging monitoring of high-voltage equipment. The GHS393 stands out for its high accuracy and long-term stability. Its robust and compact design enables use in demanding measuring locations. The output signal includes two 4-20mA analog interfaces and an RS485 interface for data transmission via MODBUS RTU.