Wear-and-tear free monitor for liquid media


Kobold Instrumentation, represented in South Africa by Instrotech – a Comtest Group company, has on offer their model NCW capacitive level monitors for liquid media, ensuring secure protection against overfilling or unintended emptying of tanks or reservoirs. The proven capacitive measuring principle for limit level detection works almost wear-and-tear free. PTFE-coating isolates the stainless steel probes from the medium and guarantees a high chemical resistance.

Four versions enable an individual choice appropriate to the measuring task. In addition to the single probe standard solution for metallic tanks, double probe versions for non-metallic tanks and for aggressive media are also available. For media with low dielectric constants, the units can also be delivered with a coaxial reference tube. A high temperature version designed for fluid temperature of max. 125°C tops off the all-round program.

The length of the measuring probes can be individually configured up to 4,000mm according to requirements. The devices are compact and beside assembly from the top, the short probes can also be installed from the side.  A pluggable electronic module is situated outside the tank in the connection head. The potentiometer and DIP switches of the electronic module enable precise adjustment of this reliable limit level detector to the respective medium. 

Working principle

The measuring system is based on the capacitive measuring method. The measuring probe and the tank wall or the second electrode respectively form the plates of a capacitor, the medium in the tank is the dielectric fluid. The capacity depends on the medium. It is low if the measuring probe is not covered (empty tank) and it increases when the medium touches the measuring probe. This change is detected by the plug-in evaluation module and is being given out as a limit
value signal.

The NCW capacitive level monitor finds application in water or waterlike liquids, liquid food, chemical and aggressive liquids, oil and pharmaceutical liquids.