IMPROVEMENTS IN AND RELATING TO LOAD MONITORING SYSTEMS AND METHODS

摘要

The invention relates to a load monitoring system for monitoring loads which are cyclically applied to a force-carrying member. The system has a transducer for producing a signal dependent on the load exerted during each cycle. A load tracking circuit (70) receives the transducer signals and generates a normal load reference signal dependent on the values of previous load signals received. A monitoring circuit (64, 68) compares the normal load reference signal with each load signal to determine when any particular load exceeds the load represented by the normal load reference signal. An inhibit circuit (72) inhibits the operation of the monitoring circuit (64, 68) during initial start-up until such time as the normal load reference signal is established. An absolute load monitoring circuit (60) detects when the load on the force-carrying member approaches the capacitor of the force-carrying member or any predetermined maximum load. The invention enables the system to take account of slow changes in the applied loads due to the effect of heat-up in operation and prevents unnecessary warning or shut down.