LM34 and LM35 are solid state temperature sensors that are most widely used in the laboratories and often deployed in appliances used in offices and houses. Before you select LM34 or LM35 as your temperature, you must have a fair idea about the the selection criterion of both the ICs. You can read Selection Criterion of LM34 and LM35 which compares the basic properties of both the ICs in way that is easier to understand. LM35 and LM34 gives 10mV/C and 10mV/F respectively. The electrical characteristic can be seen from the datasheet of National Semiconductor which you can also download from below.