## 3 Mass Evaluation of Petroleum Products Using Weighing Methods
### Mass Measurement of Bitumen  
The mass of liquid bitumen indicated on a weighing instrument has to be converted to the buoyancy-corrected mass using Equation (2). Buoyancy factor C is calculated using Equation (4). Values of volume correction factor for bitumen mass recalculation to the volume are given in the short table of ASTM D 4311 standard [48]. 4 Measurement of Petroleum Product Quantity Using Volumetric and Geometric Volume Measurement Method  
When evaluating product mass by volumetric and geometric volume measurement methods, mass is calculated using the results from several direct measurements. Using the volumetric and geometric volume measurement method, mass \(m\) of LPP in the tank is calculated using the following equation:  
\[m=V\cdot\rho, \tag{9}\]  
where \(V\) is measured product volume, \(l\), \(\rho\) is measured product density, kg/L. When using the geometric method, the LPP volume in stationary tanks is determined by using level measurements together with the tank graduation tables [31]. For the volumetric method, the meter is used for the volume flow (debit) measurement. In addition, temperature and density are measured, and then mass is calculated [49; 50]. A model for mass recalculation that evaluates the influence of volume, density, and temperature is given below [12; 51]:  
\[m=V\rho(1+\alpha(t-t_{\rm m})), \tag{10}\]  
where \(t_{\rm m}\) is the temperature of LPP, \(V\) is product's volume at temperature \(t_{m}\), \(\rho\) is measured product's density at temperature \(t_{m}\), \(\alpha\) is the coefficient of cubical thermal expansion, \(t\) is reference temperature. Under the conditions, when the assumed standard temperature is \(+\)15 \({}^{\circ}\)C, every 5 \({}^{\circ}\)C deviation from the standard temperature causes about 0.5% mass change, and respectively, each 10 \({}^{\circ}\)C deviation causes--0.95% mass change. This is a significant influence on the measurement result. In all applicable standards and recommendations main temperature correction aspects are discussed [52; 53]. Petroleum products quantification stages, using the volumetric/geometric method, are presented in Figure 5. A systematic review of the volumetric/geometric approach is presented here, highlighting the importance of accurate environmental corrections for accurate estimation in the petroleum industry. The main steps of this method are initial volume measurement, temperature and pressure regulation, density determination, and volume-to-mass conversion. The product volume at 15 \({}^{\circ}\)C temperature can be determined according to ASTM Table 54, using tank graduation table and correcting measured temperature to the reference temperature (usually 15 \({}^{\circ}\)C). Tank graduation tables are used to convert level measurement (in millimeters) to volume (in liters). Measured product density is also recalculated to the reference temperature. For this purpose, ASTM Table 53 may be used [44]. According to Equation (7), the calculated mass is called the product mass in vacuum. To calculate product mass in air, a weight correction factor (_WCF_) is used, which is selected from ASTM Table 56 [12; 54]. The weight correction factor can be calculated if the density in the vacuum and the density in the air are known [31]:  
\[WCF=\rho_{\text{a}}=\rho_{\text{vac}}-0.0011, \tag{11}\]  
where: \(\rho_{\text{a}}\) is product density in air, kg/L, \(\rho_{\text{vac}}\) is product density in vacuum, kg/L. Let's consider two methods, volumetric (flow) and geometric, discussing the instruments used, their errors, and the effectiveness of the proposed algorithm. Assume the following instruments and their accuracies are used to implement the volumetric method: the rotary chamber volume meter with an accuracy of \(\pm 0.3\%\); the temperature sensor with an accuracy of \(\pm 0.1\)\({}^{\circ}\)C; and the density meter with an accuracy of \(\pm 0.5\) kg/m\({}^{3}\) (with a density of 0.820 g/cm\({}^{3}\)).