An　improved　method　for　elastomagnetic　(EM)　effect-based　tension　measurement　is　presented　using　harmonic　analysis　technique　(HAT).　The　magnitudes　of　odd　harmonics　of　EM　signals　are　extracted　to　calculate　the　total　harmonic　distortion　(THD),　which　is　commonly　used　in　electrical　engineering　area　to　represent　the　extent　of　the　distortion　of　sinusoidal　signals.　The　value　of　THD　is　applied　for　tension　characterization.　The　EM　signals　are　acquired　by　a　EM　sensor　which　is　made　of　two　coaxial　solenoid　coils,　and　then　are　alternatively　processed　in　time　and　frequency　domain.　The　advantages　of　the　two　signal　processing　methods　are　compared　to　find　that　the　HAT　is　much　more　succinct.　The　determined　characteristic　parameters　of　calibration　equation,　such　as　linear　regression　and　slope,　tend　to　be　stable　as　the　number　of　orders　for　statistics　increases.　Moreover,　the　obtained　calibration　equation　has　better　parameters,　for　example,　the　linear　regression　is　larger　than　0.996.　The　mentioned　techniques　are　then　applied　for　measuring　the　tension　of　high　voltage　transmission　line,　the　experimental　results　testify　that　there　is　a　significant　linear　relationship　between　THD　and　the　applied　tension.　When　the　value　of　THD　is　equal　to　1,　the　relative　errors　of　estimated　forces,　which　are　calculated　from　calibration　equations　corresponding　to　various　statistical　harmonic　orders,　are　less　than　3%　(a　maximum　of　2.4%　for　seven-wire　steel　strand　and　a　maximum　of　2.9%　for　high　voltage　transmission　line).　This　study　provides　a　new　characterization　and　data　processing　method　for　EM-based　tension　measurement　technology.　©　2015　Journal　of　Mechanical　Engineering.