Vatell's Thermogage line of sensors are circular-foil heat flux transducers, also known as Gardon gauges, that have been used for measuring heat flux for decades. The all-metal construction and fully brazed joints make these sensors the sturdiest circular-foil transducers available. Many different housing designs are available to adapt to almost any application.


TG-1000 Series Water-Cooled Heat Flux Sensors Water-cooled circular-foil heat flux gauges have an active heat sink and so are less sensitive to mounting conditions, especially for applications with longer measurement times or high heat flux levels. Popular models include the standard TG1000-1, the flanged TG1000-0, and the pipe-style TG1000-30.

TG-2000 Series Conduction-Cooled Heat Flux Sensors Conduction-cooled circular foil heat flux gauges are designed for applications with short measurement times in which the total amount of heat absorbed by the gauge will not raise its temperature beyond 200°C. The basic model is the TG2000-0.


TG-9000 Series Water-Cooled Radiometers Vatell radiometers are our standard heat flux sensor with a window in front of the sensing element to screen out convection so that only radiation is measured. The window is placed directly on the water-cooled copper surface to minimize its heating, but is not in contact with the sensing element itself. Sapphire is the standard window material with a spectral range of 0.3-5 microns; its hardness and chemical resistance let it stand up to the harshest environments. Other materials, such as ZnSe (0.6-17 mircons range) are available upon request. The standard model is the TG9000-9.  

Thermogage TG-1000 TG-2000 TG-9000
Min. Std. Dia. 0.5” 0.250” 1.0”
Min. Std. Length 1” 0.5” 1”
Range (Must Specify when ordering****)* 5 to 5000 W/cm² 5 to 5000 W/cm² 10 to 500 W/cm²
Max. Sensitivity 2 mV/(W/cm²) 2 mV/(W/cm²) 1 mV/(W/cm²)
Accuracy ±3% ±3% ±3%
Repeatability 1% 1% 1%

* Minimum range for sensors without amplifiers; minimum calibration range is 5 W/cm². ** Maximum range may be limited by temperature and test duration. **** When ordering a thermogage you must specify a specific range. (Ex. I want a thermogage with a range set to 450 W/cm²) For more information, see the Thermogage User's Guide