purchase of a freeze dryer having condenser capacity: 3 - 5 kg should be capable to lyophilize samples in aqueous medium as well as in organic solvents. condenser temperature: -50 or better ice condensation chamber with high quality stainless steel inner condenser coils and drain valve for easy and quick cleaning. condenser should have sufficient condenser area inorder to avoid overload caused by too much vapour. refrigeration compression type: cfc free refrigeration with suitable safety device. freeze dryer chamber: should have in built pre-freezing unit with tray. drying chamber should be of transparent with tray dimension 200 250 mm and have minimum 4 layers. should have lcd display to show display curve. vacuum pump: vacuum degree: < 10 pa should be of high-quality corrosion resistant material and have thermal protection. system should have digital display of condenser temperature, sample temperature and vacuum for the possible range of operation.
