Instart - Instrumentation Course - Ch. 5 - Leve... |verified| Jun 2026

In the complex world of industrial process control, few variables are as visually apparent yet technically complex as "Level." Whether it is the water in a municipal reservoir, the crude oil in a refinery holding tank, or the granular raw material in a chemical silo, knowing the exact amount of material on hand is critical.

This article serves as an extensive companion to , exploring the core principles, technologies, and troubleshooting techniques necessary to master this essential aspect of instrumentation. Instart - Instrumentation Course - Ch. 5 - Leve...

| Level | Name | Typical Protocols | |-------|----------------------|----------------------------------------| | 0 | Physical process | None (physical laws) | | 1 | Field instruments | 4‑20 mA, HART, IO‑Link, Profibus PA | | 2 | Control (PLC/DCS) | Profinet, EtherNet/IP, Modbus TCP, CC‑Link | | 3 | SCADA / Supervision | OPC UA, MQTT, Modbus TCP | | 4 | MES | SQL, OPC DA/UA, Web services (REST) | | 5 | ERP / Cloud | HTTPS, SOAP, AMQP, Kafka | In the complex world of industrial process control,