Yokogawa AC1-5-S-D-R Automatic Calibration Unit

The Yokogawa AC1-5-S-D-R Automatic Calibration Unit is a single-channel system that automates zero- and span-calibration of oxygen analyzers, most commonly installed with Yokogawa ZR-series analyzers in process plants, boilers, and industrial combustion systems. It supplies zero and span calibration gases via solenoid valves, enabling analyzer-controlled or timed automatic calibration to improve measurement consistency and reduce manual maintenance in continuous monitoring applications. The unit is designed for use with the Yokogawa ZR402G analyzer equipped with the ZR22G probe. Key specifications include: operating pressure around 20 psi (max 35 psi); calibration gas flow ~0.6 LPM and reference air flow ~0.8 LPM; flowmeter range 0.15–1 LPM; gas connections 1/4" FNPT; tubing 1/4" copper (standard) with a stainless steel option; power supply typically 110 VAC or 24 VDC depending on the model; enclosure options include NEMA 4 and NEMA 4X, and it functions as a single-channel automatic calibration system with electrically actuated solenoids and a manual override.