Explore Versions

Interactive descriptions, images, and video of unique features and core technologies

Four-Sensor Design Innovation 640i/780i

Advancements to traditional thermal sensor technology for greatly improved accuracy

qTherm Technology

Learn about the revolutionary “brain” inside the instrument as well as Dial-A-Gas, Dial-A-Pipe and the qTherm Gas Library

User Interface

Push-button display & user software manages changes to the meter as well as diagnostics and tuning

Electronics & Inputs/Outputs

Information about options, configuration, output signals and digital communications

DrySense Wet/Dry Comparison

DrySense Creates Sensor Stability

Our patented no-drift DrySense velocity sensor technology uses a  proprietary swaging process which eliminates all air gaps between the heated velocity sensor and the tubular probe sheath eliminating the need for any potting compounds. The result is maximum sensitivity, reproducibility, immunity to cracking and shifting over time, and ultimately greatly improved accuracy, all backed by a lifetime warranty.

Wet Sensors Decrease Accuracy

The heated velocity sensor in other manufacturers' thermal meters is inserted into the tip of a tubular probe sheath and surrounded by organic potting compounds such as epoxy, ceramic cement, thermal grease, or alumina powder.  These so-called “Wet” sensors have  long-term measurement errors caused by aging and cracking due to differential thermal expansion between the parts of the heated velocity sensor.


DrySense Technology

DrySense Technology

DrySense is Patented, used on ALL Sierra thermal meters, has lifetime warranty
Wet Sensor Design

Wet Sensor Design

Common design used by ALL other manufacturers