Table 8.

Summary of direct and indirect measurement components and their associated uncertainties.

S.no	Parameter	Type	Uncertainty (%)	Source
1	Ambient temperature	Direct	± 0.4	Measured using calibrated thermocouples
2	Surface temperature of heat sink	Direct	± 0.75	The sensor accuracy and placement
3	Temperature of PCM	Direct	± 0.85	Multiple sensors used within PCM volume
4	Input power	Direct	± 2.4	Power = voltage × current
5	Voltage	Direct	± 0.06	Measured using multimeters loggers
6	Current	Direct	± 0.2	Ammeters
7	Thermal conductivity of PCM	Indirect	± 2	Measured via steady-state methods
8	Specific heat capacity	Indirect	± 3	DSC calibration
9	Latent heat of PCM	Indirect	± 3.5	Derived from DSC
10	Heat flux	Indirect	± 4.1	Derived from temperature gradients
11	Mass of PCM	Direct	± 0.5	Precision scales required
12	Density of PCM	Indirect	± 1.5	Calculated from mass and volume
13	Volume of PCM	Direct	± 0.75	Determined geometrically
14	Heat transfer coefficient	Indirect	± 12.5	Estimated using correlations
15	Thermal resistance	Indirect	± 6.5	Derived from temperature difference and heat input
16	Thermal diffusivity	Indirect	± 5	Inferred from material tests
17	Melting point of PCM	Direct	± 0.5	Accurate from DSC