Kobold NBK-ATEX, Operating Instructions Manual

Page: 5 / 57

NBK-03 to -33 ATEX
NBK-03 to -33 ATEX K10/0322 page 5
4.1 Bypass Measuring Tube System
The bypass tube is attached at the side of the vessel with a connecting flange or a
threaded pipe. The installation position is always vertical. The NBK should only be
used for liquids with the medium density specified on the nameplate. Otherwise the
indication will deviate (float too high or submerged).
Vessel inner pressure and medium temperature should not exceed the specified
maximum values, as this can lead to the destruction and malfunction of the bypass
system. It is imperative that the materials used are compatible with the liquid being
measured.
Proper operation is also impaired by:

high degree of soiling

suspended solids

crystallisation

ferrite particles
4.2 Electrical Limit Switches (option)
The optional electrical limit switches serve to signal a preset level.
For ATEX: NBK-RA: Bistable changeover contact as encapsulated proximity
switch fitted in metallic cast housing with 3 m connection cable.
4.3 Reed Contact Resistance Chain
(ATEX: options ...2/...E/...R/...B/...4/...L/...K/...N)
The optional reed contact resistance chain (model: MM..., see separate EC-Type
Examination Certificate LOM14ATEX2075X) converts the liquid level to a
resistance value. It serves to electrically transfer the level value. An optional
available transmitter converts the resistance value into a standard signal (e.g. 4-
20 mA).
Please pay attention to the maximum medium and ambient temperatures.