Chifukwa chiyani makampaniwa amagwiritsa ntchito zizindikiro za 4-20mA m'malo mwa 0-20mA zizindikiro?

Chizindikiro chamagetsi cha analogi chomwe chimagwiritsidwa ntchito kwambiri pamakampani ndikugwiritsa ntchito 4-20mA DC yapano kufalitsa analogi.Chifukwa chogwiritsira ntchito chizindikiro chamakono ndi chakuti sikophweka kusokonezedwa, ndipo kukana kwamkati kwa gwero lamakono sikungatheke, ndipo kukana kwa waya mu mndandanda wazitsulo sikumakhudza kulondola, ndipo kungathe kufalitsa mazana. mamita pa waya wopotoka wamba.Malire apamwamba ndi 20mA chifukwa cha kufunikira kwa kuphulika: mphamvu yamoto yomwe imayambitsidwa ndi 20mA pakali pano sikwanira kuyatsa gasi.Chifukwa chomwe malire otsika sanakhazikitsidwe ku 0mA ndikuti athe kuzindikira kulumikizidwa: sikudzakhala pansi kuposa 4mA panthawi yogwira ntchito bwino.Pamene chingwe chopatsira chathyoledwa chifukwa cha vuto, phokoso lamakono limatsikira ku 0, ndipo 2mA nthawi zambiri imagwiritsidwa ntchito ngati mtengo wa alamu wodula.