Calorific value calculation formula creation system, method of creating a calorific value calculation formula, calorific value measurement system, and method of measuring a calorific value

A measurement module is configured to measure a value of an electric signal from a heater element in contact with mixed gas. A calculation formula creation module is configured to create a calorific value calculation formula based on calorific values of the plurality of kinds of mixed gas, on measured values of electric signals from the heater element, the heater element being in contact with each of the plurality of kinds of mixed gas having a first pressure, the heater element generating heat at a plurality of different temperatures, and on measured values of electric signals from the heater element, the heater element being in contact with each of the plurality of kinds of mixed gas having a second pressure different from the first pressure, where the values of electric signals from the heater element, the heater element generating heat at the plurality of different temperatures, are independent variables, and a calorific value of the mixed gas is a dependent variable.