sentences:  The construction of the second representation is fundamentally the same as the first, however temperature and pressure sensors were implemented such that they could control the power to obtain both constant temperature and pressure for ideal operating conditions.This design is ideal for on-line LC-MS with chemical ionization and direct desorption.Given uncontrolled flow rate or varied solvent composition, another representation was designed such that a different heating source and control system would allow for partial vaporization.