Liquiphant M/S with electronic insert FEL58 + Nivotester FTL325N
Hauser
21
Wall distance
The distance between the tuning fork of the device and the wall of the vessel containing medium
(e.g. tank, pipe) must be at least 10 mm (0.39 in).
Corrosion
The device may only be used in media to which the wetted parts used are resistant. Corrosion can
have the effect that the demand mode of the safety function is not detected and the device will not
switch as intended.
Corrosion is detected with low diagnostic coverage.
If coated sensors are used, measures must be taken to ensure there is no damage during installation
and operation.
Abrasion
The device may not be used or cleaned in abrasive media. Material removal can have the effect that
the demand mode is not detected.
Abrasion is detected with low diagnostic coverage.
Flow velocity
In the case of flowing media, the flow velocity in the area around the tuning fork may not exceed
5 m/s. Higher flow velocities can have the effect that the demand mode is not detected and the
sensor signals that it is free (uncovered).
External vibration
In systems exposed to strong external vibrations, e.g. in the 400 to 1
200 Hz range (acceleration
spectral density >1 (m/s²)²/Hz) or ultrasound with cavitation, the safety function must be verified by
simulating a demand mode prior to operation. Accidental switchings may sporadically occur if a
strong frequency from an external source is superimposed on the frequency of the tuning fork.
EMC compatibility
The device is certified in accordance with IEC 61326-3-2 and is therefore suitable for safety-related,
industrial applications in a specified electromagnetic environment. If the specified electromagnetic
ambient conditions are exceeded, the switch status might not be reliably detected. An unshielded
cable up to 1
000 m (3
281 ft) long can be used between the devices in these environmental
conditions. Electromagnetic interference immunity can be further improved by using shielded cables.
Mounting the Liquiphant M FTL51 with a sliding sleeve
Particular care is required when mounting the device with a pipe extension in conjunction with a
sliding sleeve. The operator must implement appropriate measures is to ensure that the switch point
is not tampered with or that any tampering is reliably detected.