Temperature compensated annunciator

Claim 1

A temperature compensated annunciator for monitoring an amount of fillant in a pressurized vessel comprising: temperature sensor means for determining a temperature of said fillant and generating a temperature signal corresponding to said fillant temperature; pressure transducer means for measuring the pressure within said pressurized vessel and generating a pressure signal corresponding to said measured pressure; fillant amount determining means for receiving the temperature signal from said temperature sensor means and determining a calculated pressure corresponding to a minimum operational fillant level of said pressurized vessel; judging means for judging whether said measured pressure in said pressurized vessel is below said calculated pressure corresponding to said minimum operational fillant level; signaling means for signaling a user when said judging means judges that said measured pressure in said pressurized vessel is below said calculated pressure; storage means for storing a value corresponding to the measured pressure; leak detection means for determining a reduction in the amount of fillant in the vessel by comparing the pressure measured by the pressure transducer means with a previously measured pressure stored in said storage means during a given temperature cycle; and forecast means for forecasting, if said leak detection means determines a reduction in the amount of fillant, when said fillant amount will be less than said minimum operational fillant level.