Soil physics will make or break your system

Soil Thermal Resistivity

Measure, don’t guess. Even in a well-designed underground cable system, the soil may account for half or more of the total thermal resistance. Soil and backfill thermal properties should not be assumed. These properties are easy to measure in the field and in the lab. A safe, professional installation requires actual measurement and evaluation of thermal rho.

Education guides

See all guides

Thermal resistivity: Real RHO values for the professional power engineer

Understanding a soil’s thermal stability can help power engineers more accurately design power distribution systems to prevent thermal runaway.
Measurement Insights4 min read

Do bad rho values lead to power failures?

Measurement Insights7 min read

Accurate ampacity calculations depend on measured rho values. That’s why you need an accurate—and compliant—thermal properties analyzer. The TEMPOS is a fully-portable field instrument that can make measurements in as little as one minute. VARIOS is a precision lab instrument that automates thermal dryout curves, eliminating human error and wasted time. Both are backed by 40+ years of research experience on heat and mass transfer in soils.


More accurate than any thermal properties analyzer in its class, with an incredible one-minute read time.
  • Accurate thermal properties analyzer
  • New one-minute read times
  • ASTM 5334- and IEEE 442-compliant


VARIOS automatically generates complete, high-resolution dry down curves with less effort and less cost, so you can focus on what you love.
  • Automated measurement saves time and effort
  • Two measurement methods: continuous and point by point
  • Automatic temperature drift correction

Measurements made easy. Unlike competitor instruments, which use a one-sensor-fits-all type system, the TEMPOS field instrument automatically optimizes the reading for your material at the push of a button.  In the lab, VARIOS makes it easy to measure thermal conductivity as a function of water content.  Just insert the needle and start measuring. It’s that simple.

“​​For a soil instrument, it makes a lot more sense to go to people that have more expertise about soil science and soil measurements than we ever would at JPL. The thermal and electrical conductivity probe (made by METER) was probably the only instrument on the Phoenix Lander that worked perfectly from beginning to end.

 - Dr. Michael Hecht, NASA JPL

We believe in education

We're scientists. The quest for knowledge is in our blood. We've spent decades learning the best way to measure pretty much everything, so you can access a wealth of information.

Measurement Insights

See all articles

Thermal Resistivity of Stony Soils: How To Get the Right Answer in a Soil/Rock Mix

Get the right thermal conductivity or thermal resistivity value for your soil profile. Find out how to combine rock and soil measurements.
Webinars34 min watch

Thermal properties: Why the transient line heat source method outperforms other techniques

There’s no way to measure the properties of moist, porous materials with the steady state method (guarded hot plate). The transient line heat source method, however, is able to measure the thermal properties of moist, porous materials, and it can even measure thermal conductivity and thermal resistivity in fluids.
Measurement Insights9 min read

Why underground power cable installations need soil thermal resistivity measurements

Soil physics is increasingly critical in the design and implementation of underground power transmission and distribution systems.
Measurement Insights7 min read

METER is trusted by