Measure Voltage and Current Using a Data Logger

A discussion on how to accurately record AC & DC voltage with a data logger. A common data logging application is measuring voltage or current flowing into or out of a piece of equipment, such as a user monitoring current in wind turbines. These measurements can be broadly classified into two groups: AC and DC. Depending on the levels involved, some data logger models can directly measure DC voltage and current. Many data loggers can accept DC voltages up to +/- 30 volts and DC currents up to 30 mA (using a shunt resistor.) Except for power/energy application specific units, most data loggers cannot measure AC voltage or current directly and require external transducers to convert the parameter of interest into a signal that the data logger can measure and record.