Thermocouples embedded in the tool weaken the tool and cause tool failure during heavy cutting. Steel workpiece, 300 m/min surface speed. Thermal movie on the left is 300 frames per second. Field of view is about 1 mm wide. Visible light movie in the center is 10000 frames per second. Field of view is about 2 mm wide. Camcorder movie on the right is 60 frames per second. Plot on the bottom shows embedded thermocouple temperatures and a once per revolution resolver signal. For more information, see the NIST publication "Recent Experiments Assessing the Uncertainty of Metal Cutting Temperature Measurements When Using the NIST High-Speed Dual-Spectrum Optical System".