Level detection for liquid supply systems in hazardous areas

Challenge

Liquid supply systems within semiconductor Facility Monitoring and Control Systems (FMCS) handle highly flammable chemicals such as isopropanol and acetone and are therefore classified as Zone 0 or Zone 1 hazardous areas. Level detection must meet strict intrinsic safety requirements while remaining reliable under challenging process conditions. Air bubbles, chemical crystallization and changing media properties can cause false switching points and unstable signals. At the same time, sensors are exposed to aggressive chemicals, moisture and frequent washdowns. Limited installation space and time consuming on site calibration further increase commissioning effort and maintenance complexity.

Solution

TURCK’s intrinsically safe capacitive sensors, in combination with the IMX21 interface module, provide a reliable solution for level detection in semiconductor FMCS liquid supply systems. The sensors are certified Ex ia IIC T6 Ga for use in Zone 0 and Zone 1 hazardous areas and limit electrical energy directly at the measuring point to eliminate ignition risks. The IMX21 interface ensures safe signal isolation and reliable transfer of switching signals from the hazardous area to the control system, enabling seamless integration into FMCS architectures.

The sensors’ robust housing design offers high resistance to aggressive chemicals and, together with IP67 protection, ensures stable operation in wet and washdown intensive environments. Threaded installation enables straightforward mounting in compact piping layouts, while mechanical adjustment via potentiometer allows precise and repeatable configuration of switching points without complex calibration procedures. This combination reduces commissioning effort, increases measurement reliability and supports long term, safe operation of critical chemical supply processes.