GIGO means "garbage in, garbage out. One remedy that can help avoid a GIGO scenario is to understand the measurement technique and its limitations to the extent that its application can be reasonably evaluated. Differential pressure level measurement is one of those key measurements you need to understand to avoid the dreaded GIGO. The importance of level measurement cannot be overstated. Low levels can cause pumping problems and damage the pump, while high levels can cause vessels to overflow and potentially create safety and environmental problems. Vessels operating at incorrect intermediate levels can result in poor operating conditions and affect the accounting of material. The level of a liquid in a vessel can be measured directly or inferentially.