The micro ampere meter shown here is basically a DC millivolt meter.The circuit gives full scale deflection for 0.1V input.The current to be measured is passed through a known resistance R and the voltage drop across it is measured.Here the IC 1 uA 741 op-amp is wired as a non inverting amplifier.
Circuit diagram with Parts list.
- Assemble the circuit on a good quality PCB or common board.
- Use a +9V/-9V dual power supply for powering the circuit.
- The IC 1 ,uA 741 must be mounted on an IC base.
- The table given below shows the relationship between different values of R and the current that will give full scale deflection.