The Endress+Hauser Liquiphant FTL33 liquid level switch includes a piezoelectric drive that causes its tuning fork to vibrate at its resonance frequency. The built-in electronics system monitors the resonance frequency and indicates whether the tuning fork is vibrating in air or covered by liquid. The switch can be installed in any vertical or horizontal position in a vessel, pipe or tank. Foam formation, changing conductivity and density do not affect its function. EHEDG and 3-A certified, the switch is designed for food applications where CIP and SIP cleaning takes place. It has a stainless steel enclosure, with optional IP69K protection.