---Please Select--- Buchholz Relay Flow Gauges Gas Density Monitor Integrated Safety Detector Oil Level Indicator Pressure Monitor Pressure Relief Valve Rapid Pressure Rise Relay Temperature Indicator Air dehumidifiers are transparent chamber that contain salts of chemically pure silicon oxide (called silica gel). The air is sucked into the transformer via the dehumidifier, due to the thermal contraction of the oil mass. Silica gel absorbs moisture and prevents oil contamination. The colour variations are shown on the dehumidifier label. At this point, the silica gel contained in the dehumidifier must be replaced or regenerated. A special feature of silica gel is its capacity to absorb atmospheric humidity.