Why use Current excitation?
The bridges can also be powered using a precise current. Current excitation is less susceptible to electrical noise and doesn’t suffer from lead length losses. With a 4-wire load cell that is Voltage powered, the longer the lead length the lower the excitation Voltage at the resistance bridge and therefore the output is less. With current excitation the current is the same when measured anywhere in the circuit. By supplying a precise current to excite the resistance bridge and knowing the resistance of the bridge the excitation Voltage can be calculated.
