In this paper, the experimental determination of the thermal product (ρck)1/2 of ALTP sensors is presented. While literature provides thermal product values derived from individual material properties, experimental validation for complete sensor systems remains limited, highlighting the need for dedicated investigations. Using a newly developed measurement technique that enables the simultaneous and direct acquisition of heat flux and temperature in the microsecond range, the thermal product of ALTPs can be deduced. To enable comparison and validation, established experimental approaches reported in the literature, such as droplet based and plunging based techniques as well as laser based methods, are adapted and evaluated for the present sensor system. Furthermore, a novel convection-based method that adapts a stagnation-point flow procedure originally designed for sensor calibration is introduced. This new approach provides an alternative pathway with improved accuracy for determining the thermal product and supports future improvements in temperature-sensor characterization. Across all methods, the experimentally determined thermal product (ρck)1/2 consistently remains within the range of approximately 5950–6450 J m−2 K−1 s−0.5, exceeding the substrate value of 5747 J m−2 K−1 s−0.5 given in the literature, which is obtained from separately reported material properties. Fluid-based approaches (plunging and droplet) yield the lowest systematic uncertainties (Δ≈350–550), indicating high absolute accuracy. In contrast, laser-based and convection-based measurements exhibit particularly low standard deviations (σ down to 10–50), reflecting excellent measurement repeatability. The reported uncertainties primarily arise from systematic contributions associated with the calibration procedure, whereas the standard deviation characterizes the statistical scatter of repeated measurements. Thus, fluid-based methods are advantageous in terms of accuracy, while laser and convective methods provide superior repeatability. These results demonstrate a robust agreement among fundamentally different determination methods and indicate that the theoretical thermal product is likely underestimated.