| ??? 07/12/09 13:32 Read: times |
#167117 - Not really... Responding to: ???'s previous message |
Saman said:
1-the resistors have values that are harder to find. No, these series divider resistors are specially fabricated in <0.01% for this application and are better available than any other precision resistors usually! Saman said:
2- each resistor at point of solder produces a small thermocouple and with more resistors in current path we have more thermocouples. When you use these specially fabricated series divider resistors then the manufacturer already took care of thermovoltages. Also, most of your thermocouples cancel because of opposite sign. If you solder to copper (e.g.) on both ends of resistor then you have two identical thermocouples of opposite sign: "solder to copper" and "copper to solder". By the way, the most precise Amperemeters I know, use the series divider scheme... Kai |
