After passing sump pits, household wastewater is sometimes transferred to a vacuum sewerage system, which acts as an intermediary station between households and wastewater plants. Continuous measurement is needed in these tanks to ensure accurate vacuum- and sewer pump control. Once the sewage reaches a predetermined level, sewage pumps will initiate operation and transfer the sewage to wastewater plants. The vacuum pumps cycle on and off to maintain vacuum in the tank throughout this process.