UNE 21826:1983

APARAMENTA INDUSTRIAL DE BAJA TENSION. DETECTORES DE PROXIMIDAD INDUCTIVOS. FORMA D, PARA CORRIENTE CONTINUA, 3 O 4 BORNES

LOW VOLTAGE SWITCHGEAR AND CONTROL GEAR FOR INDUSTRIAL USE. INDUCTIVE PROXIMITY SWITCHES. FORM D, FOR DIRECT CURRENT, 3 OR 4 TERMINALS.