Radar Moisture Meters SONO M1, SONO M2

The SONO M is a mobile moisture meter based on Time Domain Reflectometry (TDR) technology, designed for precise measurement of moisture content in bulk materials such as sand, gravel, crushed stone, and expanded clay pellets. The series includes the SONO M1 and SONO M2 models, both equipped with integrated TDR electronics and non-insulated probe rods for direct contact with the material. The devices are compact, highly portable, and compatible with accessories such as handheld displays (HD2, SONO DIS), USB-RS485 converters (SM-USB), wireless transmitters (PICO-BT), and telescopic extensions for easy access to samples. The SONO M1 features a 64 mm probe diameter and 130 mm rod length (optionally 200 mm), while the SONO M2 is optimized for fast spot measurements in heaps, containers, or buckets.

Principle of Operation

The SONO M radar moisture meter operates using the Time Domain Reflectometry (TDR) method. A short electromagnetic pulse is sent along the probe rods inserted into the material. Part of the pulse is reflected back due to the change in dielectric permittivity caused by moisture. The propagation time of the pulse (time delay) is directly proportional to the moisture content: higher moisture slows down the signal, allowing precise calculation of the water content in the material. This method is highly robust against sample inhomogeneities, salinity, or temperature variations, delivering accurate results without the need for material-specific recalibration.

Specifications

SONO M1

• Temperature range: –15 °C to +50 °C

• Power supply: +7 V to +24 V DC

• Special features: Optional 200 mm probe rods

• Output signal: Not specified

• Interfaces: RS485

• Sensor dimensions: Ø 63 × 320 mm

• Protection class: IP67

SONO M2

• Temperature range: –15 °C to +50 °C

• Power supply: +7 V to +24 V DC

• Special features: Optionally available with telescopic extension

• Output signal: Not specified

• Interfaces: RS485 or IMP-Bus

• Sensor dimensions: 380 × 65 × 25 mm (L × W × H)

• Weight: 1.3 kg

• Protection class: IP68

• Additional features: Round GRr sensor with stainless steel cover over the temperature sensor; specifically designed for mobile use in heaps, containers, or buckets for rapid moisture determination in bulk materials.

Main Application Areas

The SONO M radar moisture meter is primarily used for mobile moisture measurement in bulk materials, including:

• Sand, gravel, crushed stone, and expanded clay pellets (SONO M1)

• Bulk materials in heaps, containers, or buckets requiring fast spot checks (SONO M2)

It is ideal for construction, mining, agriculture, ready-mix concrete plants, asphalt plants, and laboratory testing where quick and accurate non-destructive moisture assessment is required.

Advantages of the SONO M Radar Moisture Meter

• Mobility and ease of use: Lightweight and portable design for field measurements; compatible with telescopic extensions and wireless modules for hard-to-reach locations.

• High accuracy of TDR technology: Insensitive to salts, temperature fluctuations, and material inhomogeneities; no frequent recalibration needed.

• Instant results: Immediate measurement without sample preparation — perfect for on-site quality control.

• Ruggedness: IP67/IP68 protection for harsh environments; integrated electronics and durable stainless steel components.

• Flexibility: Wide range of accessories for system integration; optional longer rods for deeper measurements.