pH복합전극GST-5421C(일반용)GST-5421S(유기용매용)GST-5422S(정밀측정용)GST-5423S(정밀미량용)GST-5424C(침입용)GST-5425C(미량용)PST-5426S(미량용)GST-5427C(시험관용)GST-5428S(극세사시험관용)GST-5420C(유통용)대응기종 : HM-30V/35V/40V/50V/60V