6. Magnetic Level Gauges. These are similar to float devices, but they communicate the liquid surface location magnetically. They (see Figure 5) are the preferred replacement for the sight glasses.

As the float follows the level of liquid in the vessel, the magnet also moves up and down. The magnet activates the reed switch when they're both at the same level, providing an "on" or "off" signal.

Magnetic level gauges are suitable replacements for sight glasses. Although they are similar to float devices, the communication of the liquid surface level occurs magnetically. The float in this case ...

With a stream gauge. To measure flooding ... recording equipment to be placed directly above the float. These sensors record the water level at regular intervals and transmit the data via ...