5.1 Maintenance work to be carried out -Check the hoses, screwed connections for signs of visible damage, contamination, and leaks.-Check the electrical plug contacts for corrosion and mechanical damage (on the device and on the cables).-If necessary, the exterior of the casing of the viscosity measuring unit can be cleaned with a piece of cloth soaked with a household cleaning agent. The lower and rear sections have to be dry-treated.-In no case must liquid penetrate into the interior of the lower section.-Defective parts must be repaired or replaced with new ones.-Defective glass parts must always be replaced.nent