Sono-Vario, a more accurate way to measure moisture

The SONO-VARIO moisture level sensor uses Time Domain Reflectometry to measure the moisture of the material.
Can I take a sensor calibrated for sand and use it on other materials? Can I use AquaSense 2280D’s sampling feature for on-the-fly batch correction? Which is the best output choice, 0-10 volts or 4-20 mA? This page answers your Moisture, Frequently Asked Questions and others.
ssono-vario moisture sensor is installed in a plate beneath the aggregate feed gate
Sono Vario sensor installed on a metal plate beneath feed gate

Because it uses uses Time Domain Reflectometry, the Sono-Vario sensor can measure the  moisture of sand, fine aggregates and other granular materials within 0.1% and coarse aggregates up to 1.25″ (32mm) within 0.2%, which is better accuracy than other microwave methods.  You should position it in a plate where the material flows out of a hopper.  The sensor measures bulk moisture but you can calibrate it to read surface moisture in most materials.  View presentation

Because of the measurement technique, the microwave radiation penetrates deeply into the material, allowing it to measure a greater volume of material, which improves the accuracy.  In consequence, the Sono-Vario can measure larger sizes of aggregates with better accuracy than other microwave techniques.  For more general information on moisture measurement, see our range of Moisture Sensors.


Conveyor belt:  You should position the Sono moisture sensor in its adapter plate under the discharge from the conveyor belt.  The sensor averages the signal as the material travels past the viewing zone.

Clam gate:  You should position the moisture sensor in its adapter plate under the discharge from the gate.  The averaging starts when the gate opens and continues while the material is falling.  It stops when the gate closes.

Mixer: A different Sono sensor is available for installation in the mixer floor.  If water is added, time must be allowed for the water to be thoroughly mixed into the material.  This minimizes the error in the moisture measurement.

For an overview of all moisture related products, see Moisture Measurement. For more on different applications see Find the Best Sensor for your Appication. For a discussion of Free or Surface moisture compared with Total Moisture, click here.

“It’s a no news is good news scenario. Cameron [the operator] is happy, I’m happy, and we aren’t having any bad loads. I’m ready to start convincing others in this company to use the sensors.”
-Rod Leber, Manager, General Testing Lab.
“The probe is working great, it saves me a lot of time. I very much enjoy using it and hope to use it for years to come.”- Patrick Weaver, Asphalt Plant Management