What Is a Liquid Level Indicator?

A liquid level indicator determines how much liquid is present inside a tank, pipe, or vessel. Ultrasonic versions do this externally, sending sound waves through the container wall to detect whether liquid is present — no direct contact or internal installation required.

This approach works with many liquids and materials, including water, oils, chemicals, and food‑grade products. It is commonly used across sectors from food production to industrial maintenance.

How Do Ultrasonic Level Indicators Work?

The sensor emits a brief ultrasonic pulse that travels through the tank wall. When the pulse hits liquid, it reflects back. By measuring the return time, the device identifies whether liquid is at the measurement point.

A piezoelectric crystal and a small amount of gel ensure a stable signal path. The technique works on plastics, metals, and glass — and functions on hot or cold liquids — without draining, shutting down, or modifying equipment.

Where Are These Indicators Used?

Liquid level indicators are applied in many industries, including:

• Power & utilities: monitoring transformer and RMU oil levels

• Water management: checking storage tanks and pipelines

• Food & beverage: monitoring drink dispensers, milk tanks, and processing lines

• Chemical handling: measuring levels in resistant plastic tanks

• Marine & offshore: maintaining fluid levels in challenging environments

In real‑world use, ultrasonic indicators often outperform mechanical float gauges, providing clearer, quicker measurements.

What Is a Non‑Contact Pressure Sensor?

A non‑contact pressure sensor reads the pressure inside a sealed tank or pipe from the outside. It uses acoustic or vibrational analysis to detect how internal pressure affects the container walls. This allows for continuous monitoring without opening the system or interrupting operation.

How Does It Work?

The sensor measures the container’s natural resonant frequency. When pressure changes inside, the vibration pattern shifts. By analysing these changes — and correcting for temperature — the system provides accurate pressure readings without needing internal probes.

Applications

Non‑contact pressure monitoring is used in:

• Medical and pharmaceutical gas systems

• Food & beverage processing

• Power generation and energy systems

• Oil & gas infrastructure

• Environmental monitoring

• Aerospace, transport, and refrigeration

• Fire suppression cylinders

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