In the present work, the uncertainties of the reduced data obtained experimentally were determined. The maximum uncertainties of the investigated non-dimensional parameters are found that Reynolds number is ±5%, Nusselt number is ±9%, and friction is ±7%. The uncertainty in the measurements of the axial velocity was estimated to be less than ±5%, pressure has a corresponding estimated uncertainty of ±4%, and the uncertainty in temperature measurements at the tube wall was about ±0.5%. The experimental results were reproducible within these uncertainty ranges.