Understanding Temperature Conversion Charts
When you set up different spirit material types in the Material Type Master table (F31B04), you specify a standard temperature for the material type. Once you perform an operation on a spirit and measure the ambient temperature, the result might be higher or lower than the standard temperature. To ensure that the transaction volume is correct, the system recalculates the volume based on a temperature conversion chart that you define. Use the Temperature Chart Conversion program (P31B116) to set up a conversion chart. The system stores the temperature chart information in the Temperature Conversion Chart Header table (F31B116) and the Temperature Conversion Chart Detail table (F31B117), The temperature conversion chart lists ambient temperatures, alcohol percent values, and the conversion factor or volume modifier that the system needs to calculate the spirit volume for an operation correctly. When you set up the spirit material type, you reference the temperature conversion chart that you want the system to use for recalculating spirit volumes.
When you measure the ambient temperature or the alcohol percent value of a spirit during an operation, the values that you record may fall between two values on the temperature conversion chart. In this case, the system uses a straight-line calculation to arrive at the correct conversion factor. The following table lists the ambient temperatures in Fahrenheit, alcohol percentages, and related conversion factors for a standard temperature of 68 degrees Fahrenheit:
Ambient Temperature |
Alcohol Percent |
Conversion Factor |
|---|---|---|
60.0 F |
0.85 |
0.9800 |
62.0 F |
0.85 |
0.9920 |
66.0 F |
0.85 |
0.9965 |
60.10 F |
0.90 |
0.9700 |
62.2 F |
0.90 |
0.9880 |
66.2 F |
0.90 |
0.9960 |
For an ambient temperature of 65 degrees Fahrenheit and an alcohol percent value of 85, the system has to calculate the conversion factor because the temperature value is not listed on the chart. To calculate the conversion factor, the system looks up the two closest temperature values for the alcohol percent value of 85. In this case, they are 62 and 66. The following calculation illustrates how the system arrives at the correct conversion factor based on the specified values:
0.9920 + (¾) × (0.9965 − 0.9920) = 0.99425
If both the temperature and the alcohol percent values fall between values on the chart, the system has to perform multiple calculations. For example, if the ambient temperature is 65 degrees Fahrenheit and the alcohol percent value is 88:
0.9920 + (¾) × (0.9965 − 0.9920) = 0.99425
0.9880 + (¾) × (0.9960 − 0.9880) = 0.9920
(0.99425 × (¾)) + (0.9920 × (¾)) = 0.993125
The system can perform conversions only for temperatures that fall between the highest and lowest value that you define in the temperature conversion chart. If you enter an ambient temperature or the vessel has an alcohol percent on a spirit operation that falls outside the chart, the system issues an error message because it cannot perform the conversion.