Maintenance of valuable equipment in laboratories is very essential from the point of ensuring consistency of results over a long period of time. Like any other measurement or metrology equipment, servo hydraulic universal testing machines being high value capital goods, require regular care as these are utilized for quality assurance activities in an organization. The quality of products being manufactured depend directly on the condition of the testing instruments and equipments used to conduct the QA tests.
These machines are mainly composed of the following main sub-assemblies:
Loading frame: It consists of structural frame together with the set of grips, The cross-head positioning system, and the hydraulic actuator or cylinder that applies the load. The cross head positioning system needs regular lubrication as specified in the machine’s operation & maintenance manual. The actuator or hydraulic cylinder needs inspection for leakages if any from the seals
Hydraulic power pack: This is the source of power required for the loading of the sample, and requires regular inspection of temperature of hydraulic oil, the level of oil in the reservoir, leakages, the condition of the electric motor and more importantly, the valve system which delivers accurate pattern of loading. The condition of the pipes and the cabling also needs to be checked. The oil filter provided, needs to be cleaned, and replaced as per manufacturer’s recommendation. Delay in filter replacement may hamper the oil flow and hence the loading will be adversely affected.
Control System: The system is used to preset the loading condition and the selection of measurement parameters that will be displayed and reported. The whole of the equipment is calibrated from the control system and this ensures accuracy and traceability of results. More often, such equipment use dedicated software installed on a personal computer. This part therefore needs IT care as failure or hanging og computer may render the complete equipment under expensive downtime. Computers are prone to security issues coming from compatible networks and devices connected for data transfer.
In conclusion, each sub-assembly and critical part requires regular maintenance and the same must be in strict accordance with the schedules recommended by the manufacturer in the operation and maintenance manual.