Igwe okpu okpu karama ejiri aka na-arụ ọrụ maka okpu karama mmanya, mkpuchi iko mmiri mbugharị, wdg.
Nlereanya a bụ igwe mgbakọ pendulum kacha ọhụrụ nke nwere akụkụ abụọ ruo ise nke APM mepụtara wee mepụta ya nke ukwuu. A na-eji ya eme ihe maka ịgbakọta okpu karama dị iche iche ma dị mma maka ikpokọta okpu karama dị iche iche na obere obere na nnukwu ụdị. Dị ka ihe atụ: mmanya karama okpu, ibugharị mmiri iko okpu, wdg, nwere ike ime ka dị iche iche chọrọ iji gboo mkpa mgbakọ.