With the lower left toggle switch set to the right-side, the meter reads AC (pseudo-RMS). When measuring AC, the meter is not sensitive to DC or to the offset settings. Accuracy is +/-3% in the interval 45Hz - 2000Hz. The -3 dB frequency interval is 16Hz -20KHz, although frequencies above 2000Hz may induce falsely high readings because of inductive pickup.

Remember to return the toggle switch to the left position for standard (DC) measurements. Only areas close to a transformer, a motor, a fluorescent ballast, or a wire carrying AC current will produce a significant AC reading. Other areas will produce near-zero AC readings. A wire carrying 10 amps AC (RMS) will yield a reading of 1.8 gauss AC, at a distance of 1 cm from the wire. Magnetic field is proportional to current divided by distance from the wire, for a single long wire.