An adjusted intensity-ratio temperature-dependent (IR-TD) method was used for temperature estimations and validated by comparison with two different IR-TD methods. The precision was in the range of (2.76-5.1)%. A mixture of white phosphor powder and an adhesive agent was used for coating 7 points at the front surface of PMB. These points were regularly distributed, where the most vital points were incorporated. A pulsed laser at 355 nm and a laser power of 54 mJ/pulse was used for phosphor excitation. The laser beam was directed onto each point at an exposed area of around 0.75 mm2. The phosphor was dysprosium-erbium double-doped: yttrium aluminium garnet (Dy:Er:YAG). The operating points of PMB were taken, 1000 W and 2000 W for thermal loads, 0.7 and 0.8 for equivalence ratios.