Patent ID: 8667829

Claim:
A breath test simulator for producing breath test vapor having a known concentration of ethyl alcohol at a simulator outlet port for flow from the outlet port, through an outlet tube to a breath test analyzer; the simulator comprising a container adapted to receive a water/ethyl alcohol solution having a known concentration of ethyl alcohol; a top housing comprising a lid closing the top of the container and a one-piece thermally conductive metal body, the metal body forming at least a portion of the lid and including a thermal mass extending a distance above the lid and having an exterior surface above the lid; an inlet port on the thermal mass exterior surface; an inlet passage in the thermal mass and lid extending from the inlet port to the interior of the container; an outlet port on the thermal mass exterior surface; an outlet passage in the thermal mass and lid extending from the interior of the container to the outlet port, wherein said one-piece thermally conductive body forms the interior walls of said passages; a first heater on said metal body for heating the lid by conduction to heat the head space in the container and for heating the thermal mass by conduction to heat the inlet and outlet passages; a first control circuit for actuating and deactuating the first heater to maintain the temperature of the head space within a first operating range; a second heater located in the interior of the container; and a second control circuit for actuating and deactuating the second heater to maintain the temperature of a water/ethyl alcohol solution in the container within a second operating range; wherein said first heater heats both inlet air flowed through the inlet passage and into the interior of the container and breath test vapor flowed through the outlet passage to the outlet port by conduction through the metal body.