Non-Contact Ultrasonic Level Switch for Metal Grain Silos

1. Why You Need It

Grain silos hold bulk solids that damage contact probes and produce dust that fouls optical sensors. This non-contact ultrasonic level switch detects silo level from above without touching the grain, using analog current/voltage output for seamless control integration. It provides dependable high/low level detection for metal grain silos, protecting against overflow and empty conditions without the maintenance burden of contact sensors.

2. Working Principle

The switch uses ultrasonic echo-ranging to measure the distance from the sensor to the material surface inside the silo. Because it is non-contact, there is no probe to wear against grain or clog with dust. The sensor outputs an analog current or voltage signal (plus switch output) that the control system uses for level alarming and feed control. The 24 V supply and robust construction suit the demanding silo environment.

3. Key Advantages

• Non-contact level detection
• Built for metal grain silos
• Analog current / voltage output
• NPN + PNP switch output
• 24 V DC supply
• Dust-proof operation
• No probe wear from grain
• Reliable high/low detection
• Suitable for bulk solids
• Low maintenance

Common Pain Points & Solutions

Application Cases

Technical Specifications

FAQ

Q: What is an ultrasonic level switch for grain silos?

It is a non-contact level switch that uses ultrasonic echo-ranging to detect the grain level inside a silo from above. Because it does not touch the grain, there is no probe to wear or clog, making it ideal for bulk solids storage.

Q: Why is non-contact measurement important for grain?

Grain is an abrasive bulk solid that wears down contact probes, and silo dust fouls optical sensors. Non-contact ultrasonic measurement avoids both problems, providing reliable, low-maintenance level detection.

Q: What output does it provide?

It provides an analog current or voltage output for continuous level indication, plus NPN and PNP switch outputs for high/low level alarming. This dual output supports both monitoring and control.

Q: What power supply does it need?

It operates on 24 V DC, the standard for industrial control systems. This supply integrates directly with silo control panels and PLC systems.

Q: How does it detect level?

It emits an ultrasonic pulse toward the grain surface and measures the time for the echo to return. The distance to the grain surface is calculated, and the level is compared against set high/low thresholds for alarming.

Q: Does it work in dusty conditions?

Yes. Ultrasonic sensors are largely unaffected by dust, which is a major advantage over optical sensors in grain silos. The sound-based measurement continues to work reliably in dusty environments.

Q: How is it mounted?

It is mounted at the top of the silo, pointing down at the grain surface. The non-contact design means there is no probe extending into the grain, and the output wiring connects to the control system.

Q: Can it prevent overflow and empty conditions?

Yes. The high/low switch outputs trigger alarms when the grain reaches the high (overflow) or low (empty) threshold, enabling automatic feed control and preventing overfilling or dry-run.

Q: What materials is it made for?

It is designed for grain and bulk solids such as feed grain and flour. The non-contact sensing principle makes it suitable for any material that reflects sound.

Q: Where is it used?

It is used in metal grain silos, feed storage silos, flour mill grain bins and bulk storage hoppers. It provides reliable, non-contact level detection for grain and bulk solids storage.