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COWBOY WAFER for thermal chuck calibration and surface temperature measurement – made for global service mobility

We specialize in calibration of temperature sensors, surface temperature measurement and characterization..

Sigma Sensors is a mobile Temperature Calibration Laboratory. We can perform most calibrations not just in our lab but also at your site. As our processes and systems are evolving, we expect full ISO17025 accreditation by Q1/21.

Why calibrate: Calibrated sensors have inherently improved accuracy specifications over DIN spec sensors as seen below. The colored graphs depict uncertainty as per accuracy class specification., At 200 degrees Celsius these range from +-0.5C to +-2.5C compared to a calibrated sensor whose accuracy can be as low as +-0.03-0.05K, k=2. This makes a SiGMA K2 sensor more accurate by a factor of 10.

The initial calibration process is performed by physical immersion into a temperature source. Results are compared to the values of a known traceable standard (ITS90) calibrated thermometer.

Our calibrated sensors get installed in the COWBOY WAFER, a <4mm Si wafer sandwich. Physical contact is optimized and outside influences minimized. This enables us to accurately measure the temperature of the wafer and therefore get a picture of the temperature distribution of the thermal chuck.

The COWBOY WAFER comes in both 200mm and 300mm versions in 5-17 sensor configuration. Standard measurement uncertainty ranges from 0.25K for Thermo-couples to <0.1K for PT sensors. Standard uncertainty is +- 0.15K from -40/45/60C to +140/175/200 degree Celsius.

Only a finite number of sensors can economically be placed on a wafer. We invented the hybrid IR temperature measurement concept in 2007 and perfected the corresponding wafer in 2020.

Hybrid IR temperature characterization wafer 200mm/300mm

•-45C to +200C – determined by camera

•For use with air and/or water-cooled cameras

•1-4 integrated, calibrated reference sensors for normalization of temperature data

•Comprehensive surface map for detailed temperature gradients, each pixel a data-point

•Resolution <0.1C camera dependent

•Accuracy to 0.1K over whole range

•No high temperature flicker, low temperature capable to -40C


SIGMA SENSORS COWBOY WAFER comes as a complete, rugged, easy to use temperature calibration system. The case integrated dataloggers are hardwired to the wafer interface cable. Above the electronics compartment is the wafer storage.

The notched wafer gets placed on the thermal chuck, the cables get plugged into the corresponding wafer tails, The USB out end from the case gets plugged into the computer and the system is ready for acquiring live data.


  • Real-time data collection and display
  • Visual logger and channel setup for easy configuration and viewing
  • Available for Windows 7, 8 and 10 (32 and 64-bit), macOS, Linux and Raspbian for Raspberry Pi
  • Virtually unlimited logging capacity to PC
  • Robust database format minimizes data loss and corruption
  • Simple and complex programmable alarms
  • Up to 4 independent graph axes
  • Data can be exported as CSV, clipboard image and PDF


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