Milliamp process clamp meters can measure mA signals without breaking the loop. The Fluke 773 mA Clamp Meter is Flukeās premier mA Clamp Meter, providing you with the best in troubleshooting and process calibration power.It expands upon the capabilities of the popular 772 mA Clamp Meter, adding voltage measure and source, scaled mA output, and mA in/out.