ENDRESS+HAUSER  FTL325P-O1A1

• Point level detection in liquid tanks and bulk solids silos, also in hazardous areas
• For sensors in Zone 0 or Zone 20
• Liquid detection in pipes for dry-run protection of pumps
• Overfill prevention in tanks with flammable or non-flammable water-polluting liquids
• Two-point control and point level detection in one switching unit
• Application in safety systems with functional safety requirements up to SIL 3 in accordance in IEC 61508 when using the Liquiphant M/S with electronic insert FEL57

• Intrinsically safe signal circuits [Ex ia] for use of sensors in hazardous areas
• Compact housing for simple side-by-side installation on standard DIN rails in cabinet
• Easy connection with plug-in terminal blocks
• Simple proof testing according to WHG with a Liquiphant M/S connected: one-touch operation
• High proof test coverage: from the Nivotester to the sensor and downstream plant units

The intrinsically safe signal inputs of the Nivotester are galvanically isolated from the mains and the output.

The Nivotester supplies direct current to the sensors, e.g. Liquiphant M/S, via a two-wire loop and receives a frequency signaling whether or not the point level has been reached. Current pulses (PFM signals = pulse-frequency modulation) from the transmitter with a pulse width of approx. 200 μs and a current strength of approx. 10 mA are superimposed on the power supply.

The Nivotester evaluates the frequency and switches the output relay for the level alarm. A yellow LED on the front panel of the Nivotester indicates the relay switching state.

By selecting the correct fail-safe mode, you ensure that the relays always operate with quiescent current safety.

MAX = maximum safety: the relay drops out when the switch point is exceeded (sensor is covered), a fault occurs or the power supply fails.

MIN = minimum safety: the relay drops out when the switch point is undershot (sensor is not covered), a fault occurs or the power supply fails.