Iowa Code Title V. Agriculture [Chs. 159-215A] § 215.20. Liquid petroleum gas measurement

1. All liquefied petroleum gas, including but not limited to propane, butane, and mixtures of them, shall be kept, offered, exposed for sale, or sold by the pound, metered cubic foot of vapor, defined as one cubic foot at 60 degrees Fahrenheit, or by the gallon, defined as two hundred thirty-one cubic inches at 60 degrees Fahrenheit.

2. All metered sales exceeding one hundred gallons shall be corrected to a temperature of 60 degrees Fahrenheit through use of an approved meter with a sealed automatic compensation mechanism. All sale tickets for sales exceeding one hundred gallons shall show the stamped delivered gallons and shall state that the temperature correction was automatically made.

3. A reasonable tolerance within a maximum of plus or minus one percent shall be allowed on liquid petroleum gas meters licensed for commercial use in this state.