IMKO Radar Moisture Meters

IMKO radar moisture meters are advanced sensors for precise measurement of moisture content in bulk solids (grain, soil, raw materials) based on TRIME TDR (Time Domain Reflectometry) and SONO (combined radar + ultrasonic) technologies. They enable continuous inline monitoring, mobile testing and lifecycle control of materials. The range includes models such as SONO-GS1, TRIME-GWs with GR probe, SONO VARIO LD, SONO-MIX and PICO 64/32, all highly resistant to contamination, delivering accuracy of ±0.3 % to ±2 % and operating in harsh conditions (-40…+80 °C). Ideal for process automation in agriculture, food production and construction.

Operating Principle

IMKO moisture meters use TDR technology: a short electromagnetic radar pulse is sent along metal rods or a cable inserted into the material. Water dramatically changes the dielectric constant (εr), which alters the propagation velocity and reflection time of the pulse. The sensor calculates moisture content from the measured runtime. SONO models additionally use ultrasonic pulses to determine material density and automatically compensate for it. The systems are insensitive to salinity, temperature fluctuations and mechanical stress, and require no recalibration for many materials.

Characteristics by Series

TRIME-GWs

• Moisture range: 0…40 % (material-dependent)

• Accuracy: ±1–2 %

• Probes: GR screw probe for grain, lengths up to 1 m

• Features: Portable for mobile grain testing, Bluetooth, IMKO CONNECT app, –10…+50 °C, rechargeable battery

• Application: Grain moisture at elevators and farms

SONO-GS1

• Moisture range: 0…50 %

• Accuracy: ±0.5 % (grain)

• Features: Compact inline sensor, RS485 / 4–20 mA, IP67, –40…+80 °C, combined TDR + ultrasonic

• Application: Continuous grain drying control

SONO VARIO LD

• Moisture range: 0…100 %

• Accuracy: ±1 %

• Probes: Adjustable length up to 2 m, for low-density materials

• Features: Modbus RTU, antistatic design, –20…+60 °C, no calibration needed

• Application: Uranium concentrate, wood chips, lightweight aggregates

SONO-MIX

• Moisture range: 0…40 %

• Accuracy: ±0.8 %

• Features: For mixed and inhomogeneous bulk materials, 4–20 mA / HART, IP68, –40…+85 °C, automatic density compensation

• Application: Animal feed, biomass, mixed aggregates

SONO-M1 / M2

• Moisture range: 0…60 %

• Accuracy: ±1.5 %

• Features: M1 for bulk solids on conveyors, M2 for construction materials; Ethernet / Profibus, –30…+70 °C, durable ceramic probe

• Application: Food industry and building materials

PICO 64/32

• Moisture range: 0…100 %

• Accuracy: ±0.3 % (lab grade)

• Features: Laboratory and handheld versions, USB, 0…+40 °C, scan in seconds, very small sample volume

• Application: Laboratory analysis of raw materials

Main Application Areas

Moisture monitoring of bulk solids in agriculture (grain, feed), food & beverage (flour, sugar), construction (sand, cement), energy (biomass), and scientific soil research. Used in silos, conveyors, dryers, mixers and laboratories where real-time moisture data is critical for process optimisation and quality control.

Advantages of IMKO Radar Moisture Meters

• Extremely high accuracy and repeatability (±0.3 % to ±2 %)

• Completely insensitive to contamination, salinity and temperature swings

• No recalibration required for most materials

• Simultaneous moisture + bulk density measurement (SONO series)

• Mobile and inline versions, easy integration (Bluetooth, 4–20 mA, Modbus, etc.)

• Rugged design, service life > 10 years, minimal maintenance

• Significant cost savings through prevention of spoilage and optimal drying

About IMKO Micromodultechnik GmbH

Founded in 1984 , Germany, IMKO Micromodultechnik GmbH is a leading developer and manufacturer of moisture measurement systems based on proprietary TRIME® TDR technology. IMKO offers 198 products, operates in 153 countries via 86 partners and has received multiple innovation awards (e.g. Dr. Rudolf Eberle Prize 1993). Its mission is to provide reliable, high-precision moisture solutions for agriculture, construction, food production and research.