You have not mentioned anything on the nature or other properties of the body under your test consideration. However, considering it as a usual one, but desiring more scientific accuracy, the following thermometric means may be adopted for your quick execution and implementation.

(a) An empirical technique by generating the thermodynamics triplet correlation functions, or

(b) A innovative technique, developed after Eq. 9-74 and given in Page-616, in a book entitled "Advanced Transport Phenomena: Fluid Mechanics and Convective Transport Processes" by L. G. Leal.

The body can be a brick or asphalt.

@p.k.

At the initial stage, you may refer to the following

Reference 1: Data collection I used a Raytek Raynger ST IR thermometer to collect surface temperatures and a thermo-hygro digital thermometer to collect air temperatures. I measured both types of temperature readings 1.5 m above the surface and at least 1.5 m from the material’s perimeter (Asaeda, Ca, & Wake, 1996). I collected temperature measurements for each material during the warmest time of day, generally between 2 p.m. to 4 p.m. and took the average of 4 surface temperature readings. In order to collect stable air temperature readings, I took measurements when there were no winds. Link: https://nature.berkeley.edu/classes/es196/projects/2011final/GuanK_2011.pdf

Reference 2: A simple method is proposed to calculate the maximum pavement temperature profile on the basis of maximum air temperature and hourly solar radiation. The method was developed to be used mainly for Strategic Highway Research Program binder and mixture specifications and as a quick method of determining maximum pavement temperature for various regions in the United States and Canada. The method is based on the energy balance at the pavement surface and the resulting temperature equilibrium. Reasonable assumptions are made regarding thermal properties of the asphalt concrete. The accuracy of the method was tested by applying it to some field cases for which measured pavement temperatures were available. Link:

http://onlinepubs.trb.org/Onlinepubs/trr/1993/1417/1417-001.pdf

Reference 3: A STUDY OF THE SURFACE TEMPERATURES OF SIX GROUNDCOVERS ON THE FROSTBURG STATE UNIVERSITY CAMPUS

Link: https://www.frostburg.edu/fsu/assets/File/clife/mscenter/FinalPapers/2008/Heat.pdf

Best Wishes