The Rosemount 3900 and 3900VP general purpose pH/ORP sensors feature a double junction reference that protects against poisoning ions (ammonia, chlorine, cyanides, sulfides), resisting harsh environments and prolonging sensor life. Porous Teflon junction positioned near the pH/ORP‑sensitive membrane. AccuGLASS pH glass resists cracking at high temperatures and reduces sodium ion error in high pH applications.

Model 3900VP offers a watertight sensor‑to‑cable Variopol connector eliminating rewiring and cable twisting. Housed in molded PPS body, virtually indestructible and chemically resistant. Complete encapsulation eliminates leakage or high humidity problems. No electrolyte replenishment required. 1″ and 3⁄4″ MNPT front‑facing connections for insertion, submersion, or flow‑through.

Compatible with Rosemount Analytical and other manufacturers’ instruments. SMART enabled. Suitable for pipelines, open tanks, ponds, and virtually all applications.