## 4 Results and Discussion
Therefore, viscosity change in temperature (\(\dfrac{d\mu^{*}}{dT}\)) and the wall temperature change in time (\(\dfrac{dT_{w}}{dt}\)) can only have a multiplication or a division effect in Figure 19b. After these parameters are added, the new graph appears as in Figure 9:7  
Figure 9:8 (**a**) Ratio of \(T_{c}/T_{w}\) in percentage as the Fourier number increases. (**b**) Temperature difference as the Fourier number increases. To achieve a minimum error in temperature measurement, the Fourier number is assumed to be 1. Under this condition, the optimum settling time that results in the lowest temperature measurement error is determined. By setting the Fourier number to 1, the study aims to determine the most suitable settling time that results in highly accurate temperature measurements. This finding is of great importance for improving the precision of viscosity measurements and contributes to the advancement of experimental methods in heat transfer analysis. Establishing an optimal settling time is a critical step in minimizing potential errors in temperature-dependent viscosity measurements, thereby improving the overall reliability and applicability of such analyses in various research and industrial contexts. Figure 9:9  
As a result, a new non-dimensional parameter known as the Akpek number emerges from the multiplication of the change in the viscosity by temperature (\(\frac{d\mu^{*}}{dT}\)), the temporal variation in the edge temperature of the fluid (\(\frac{dT_{w}}{dt}\)), and the time parameter derived from the Fourier Number. Figure 10:0  
For the special case where the Biot number is zero and the Fourier number is one, Figure 21 shows the relationship between the Akpek number and the viscosity measurement error, which is directly linear with the temperature difference. This graph is based on the data of the Heisler diagram. This research result provides valuable insight into the influence of various parameters on viscosity measurement accuracy, especially in scenarios where temperature variation is significant. The Akpek number provides a comprehensive approach to quantifying the acceptable rate of heating and enables the design of effective heating systems and vessels for different types of fluids. The relationship presented between the Akpek number and viscosity measurement error serves as a practical guide for optimizing viscosity measurements in various experimental setups and industrial processes. Figure 10:1 Temperature difference and its relationship with Fourier number, viscosity change rate in temperature (\(\frac{d\mu^{*}}{dT}\)), and the wall temperature change (\(\frac{dT_{w}}{dt}\)) in time. From the obtained results, it can be deduced that an Akpek number of about 9.5 is required to achieve zero viscosity measurement error for the sample fluid. The Akpek number serves as a crucial parameter in designing vessels or determining the heating rate for any type of fluid, either independently or interdependently. If the specific properties of the sample vessel are known, the Akpek number can be used to determine an optimum heating rate. Moreover, the versatility of the Akpek number formulation allows its adaptation to different scenarios in which the Biot number or the Fourier numbers differ from the aforementioned values. By changing the \(t^{*}\) number accordingly, the Akpek number can be adapted to different conditions, ensuring accurate viscosity measurements for a wide range of applications. This approach holds significant potential for improving the precision of viscosity measurements and facilitates the development of efficient heating systems for various liquid media.