Professional AC TRMS clamp meter with 400A current measurement and power/harmonics analysis. HT4022 measures RMS AC current up to 400 A, AC/DC voltage up to 600 V, frequency, resistance, circuit continuity, active, reactive, and total power, Cos₂, and energy for balanced single-phase and/or three-phase systems. It also determines phase sequence using a single-pole method. The HT4022 model additionally performs absolute and percentage measurements of harmonic components of voltage and current with THD% calculation. Each device complies with IEC/EN61010-1 CAT III 600V standards and is suitable for troubleshooting typical industrial issues such as nonlinear loads and variable frequency drives.