Cannon HTHS Series II Instruction & Operation Manual

Cannon HTHS Series II Instruction & Operation Manual Manual pdf 28 page image

25CANNONCANNONCANNONCANNONCANNON® High-Temperature High-Shear Viscometer Series II Instruction & Operation ManualRevision 1.0d—June, 2011;CANNONCANNONCANNONCANNONCANNON® Instrument Company2139 High Tech Road • State College, PA 16803 • USACHAPTER8 MAINTENANCE & REPAIRFlushing viscometer cellsCANNON® recommends that all five cells be flushed at the conclusionof testing each day with approximately 5 ml of a low viscosity neutral oil(2 mPa·s at 150°C) or commercially-available Stoddard solvent. This isespecially important if the HTHS viscometer is maintained at tempera-ture for an extended period without running sample, as many automotiveengine oils will carbonize if left in the cell for long periods at hightemperatures.Clearing a blocked capillary tubeErratic HTHS measurements may suggest a blocked orpartially blocked capillary tube. If the capillarybecomes blocked or partially blocked, it will usuallyneed to be removed for cleaning. A solvent flushshould be attempted first if the symptoms suggestpartial blockage.Cleaning the capillaryIf the flush fails to remedy the blockage, follow thechecklist below to clean the capillary. You will needtwo wrenches, a small screwdriver and a narrow gaugewire (less than 0.15 mm) to perform portions of theoperation. You will also need two replacement gasketsand a #400 mesh filter screen (available from CAN-NON®—see HTHS replacement parts list, Chapter 9):Preliminary disassembly Prior to cleaning, follow the instructions in APPEN-DIX A for removal and disassembly of the viscometriccell.After removing the capillary, remove and discard thegasket and filter screen from the capillary support. Thescreen and gasket (see photo) may remain in the celleven after the capillary has been removed. If so, youwill need to use a small tool similar to a dental pick toremove these items from the interior of the viscomet-ric cell.