## 6 Conclusions
However, it is crucial for companies to be aware of this potential discrepancy and to have clear contractual agreements with suppliers and customers regarding the measurement and reporting of LPG quantities. Transparency and consistency in measurement practices are essential for maintaining trust and fairness in the petroleum trade. Although we acknowledge that the buoyancy coefficient does not affect the mass value of LPG in closed tanks, this does not apply to corrections related to the calibration or adjustment of weighing instruments. Therefore, a company's loss management strategy should include investments in higher-precision measuring instruments (e.g., static weighing scales for cars and wagons with a verification scale division value of 20 kg, and 0.2% dynamic weighing scales for wagons). Additionally, regular maintenance of these instruments is crucial. Measurement errors can be reduced by applying known corrections to individual measurement results through calibration and verification protocols. If there are systematic positive or negative deviations in measuring instruments, or if the weighing errors exceed their verification scale interval, a correction may be applied to the measurement results. The results may be uncorrectable if average weighing errors are smaller than the verification scale interval. Ideally, weighing errors should be randomly distributed within the permissible error range for individual measurements. For all operations where applicable, it is advisable to use scales of the same accuracy class, with the same verification scale division value and weighing mode [58; 59]. To eliminate inconsistencies arising from the application of air buoyancy corrections and to ensure consistent mass-to-volume conversions in petroleum transactions, it is recommended to establish clear and unequivocal requirements for measurement protocols and the reporting of results. For comparable quantities, only unambiguous results, expressed in consistent units and representing the same physical property, should be compared. When comparing weighing results, direct comparisons (in terms of physical quantities) are valid: \(m_{a1}\Leftrightarrow m_{a2}\) (where \(m_{a1}\) and \(m_{a2}\) represent weighing results in air). For comparisons between weighing results and volume: \(M=m_{a}\cdot\text{C}_{\text{buoyancy}}\), \(V_{1}=M/\rho_{15}\), \(V_{2}^{15}=V_{2}^{t}\cdot VCF_{2}\), \(V_{1}\Leftrightarrow V_{2}^{15}\);  
For comparisons between volume and weighing results: \(V_{1}^{15}=V_{1}^{t}\cdot VCF_{1}\), \(M_{1}=V_{1}^{15}\cdot\rho_{15}\), \(M_{2}=m_{a2}\cdot\text{C}_{\text{buoyancy}}\), \(M_{1}\Leftrightarrow M_{2}\);  
For comparisons between two volume measurements: \(V_{1}^{15}=V_{1}^{t}\cdot VCF_{1}\), \(V_{2}^{15}=V_{2}^{t}\cdot VCF_{2}\), \(V_{1}^{15}\Leftrightarrow V_{2}^{15}\); (where \(m_{a}\), \(m_{a2}\)--mass determined by weighing in air, \(\text{C}_{\text{buoyancy}}\)--air buoyancy correction factor, \(M\), \(M_{1}\), \(M_{2}\)--mass of product in vacuum (corrected for air buoyancy), \(\rho_{15}\)--product density at 15 \({}^{\circ}\)C, \(V_{1}\)--volume of product (corrected to reference temperature), \(V_{1}^{t}\), \(V_{2}^{t}\)--volume of product at temperature \(t\), \(V_{1}^{15}\), \(V_{2}^{15}\)--volume of product corrected to 15 \({}^{\circ}\)C, \(VCF_{1}\), \(VCF_{2}\)--volumetric correction factor (used to convert volume at temperature t to volume at 15 \({}^{\circ}\)C)). To ensure the company's material balance (when purchasing raw materials, in internal production processes, and when selling products) and to minimize losses, it is crucial to adhere to general, uniform quantity calculation provisions throughout the entire purchase-production-sales chain. This means that in all cases, it is necessary to calculate the mass in vacuum and the volume at +15 \({}^{\circ}\)C, regardless of whether direct weighing with scales or indirect mass recalculation from volume and density is applied.