The test cells require some maintenance after each use. The environment of the test makes the cell prone to corrosion.   In order to clean the cell, one must:  Disassemble the test cells, removing all parts.    Clean the steel mesh plate and connector to remove all the rust. We recommend using CLR solution or any equivalent product.   Reassemble the cell making sure the connectors are tightened, and the metal head of the connector inside the cell is completely in contact with the wire mesh. If the connectors are loose, signs of corrosion will appear on the edge of the wire mesh, which may cause errors in the measurement.   You can check the connection between the mesh and the connector using a Voltmeter.