Hello, I'm implementing a current sensing circuit as shown in the schematic. The simulation works but the physical circuit does not. On the breadboard if I measure between the shunt and the load to the ground on the power supply I get 67.3mV, however if I measure across the shunt I get 27mV (expected value since current @ 100ohm load is 110mA). As a result the Op-Amp amplifies the 67.3mV and I get the wrong amplified voltage. I've connected all the ground rails together and to the power supply. Can anyone say what's the possible problem ?
EDIT: I changed the shunt resistor to 1ohm and it works as expected, so why doesn't it work with the 0.25 ohm shunt ?