Oil Level Indicator
Monitoring and maintaining oil level in gear boxes is bit of a problem. There are primarily two methods of inspecting oil level in gear boxes.
Dip stick: gear box manufacturers provide a dip stick on top of gear box. This dip stick has two markings viz. 'hi' & 'lo'. Ref. Fig. 1. When gear box is not running oil level has to be at hi, whenever oil level goes below 'lo' oil has to be added. The difficulty is how to know whether oil level has gone below 'lo'. Stopping the gear box to check oil level is neither convenient nor practical. Gear boxes are often located at odd locations wherein operators seldom check oil. In a typical process plant there are dozens of gear boxes, maintaining oil level with dip stick technology is a herculean task. There is a definate chance that a few gear boxes are running even below 'lo' oil level. The cost of breakdowns, replacement of expensive gears and bearings are indeed phenomenal.