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SYSTEM
3.2.2 SOIL SAMPLE RING
The soil sample ring is designed to be pushed in the ground to collect a soil sample that is
the appropriate volume for VARIOS testing. There are two holes drilled into the ring to allow
for insertion of the VARIOS TC-S70 needle, with one extra hole in case debris is encountered.
Two plastic protection caps are included to transport samples from the field to the lab.
3.2.3 HYPROP BALANCE
The HYPROP balance continuously measures the weight of the sample, which allows the
software to calculate water content of the sample as it dries.
NOTE: USB and HYPROP port, weighing range 2,200 g, resolution 0.01 g, reproducibility 0.01 g, linearity 0.01 g
3.2.4 SATURATION RING
The VARIOS sample saturation ring assists in soil saturation, and prevents soil loss during
the saturation process.
3.2.5 SILICONE RETAINING RINGS
The silicone retaining rings hold the sensor in place to prevent movement during the duration
of the test. This prevents air gaps between the sensor and the soil.
3.2.6 USB-A TO USB-B ADAPTER AND CABLE
This cable will connect the VARIOS to a computer. This component is required to use the VARIOS.
3.2.7 GLYCERIN VERIFICATION STANDARD
The glycerin standard is used to verify that VARIOS sensors are reading correctly. Glycerin
has a known thermal conductivity of 0.285 W/m K as long as it is stored properly. If the
standard needs to be replaced, additional glycerin can be purchased from any chemical
supply store.
3.2.8 UPPER ADAPTER
The upper adapter guides the sensor into the glycerin verification standard and ensures the
sensor is in optimal position for sensor verification.
3.2.9 LOWER ADAPTER
The lower adapter holds the glycerin standard vial in place for sensor verification.
3.3 THEORY
The VARIOS measurement principle is based on the transient line heat source method,
which has been used to measure thermal conductivity of porous materials for over 60 years.
Typically, a probe for this measurement consists of a needle with a heater and temperature