Get current pricing for Hm Digital, PSC-154 Hm Digital Psc-154 Ec/tds Controller With 4-20 Ma Signal With 0-5000 Ppm Tds Range, 0-9999 Us Ec Rane, 1-75 C Temperature Range. A +/- 2% Accuracy And . Product Category: Process Equipment, Sub Category: Instrumentation: