The controller/pump is enclosed in a modular housing for maximum protection. The pump utilizes a one-piece polypropylene, injection-molded housing. Since there are no joints or screws holding different sections of the housing together, the case is extremely rugged and sturdy. This series of instruments will mount easily in your plant using a minimum of wall space. The controls and pump head are located in the front to allow easy access. pH Controller and dosing pump in one compact unit. +/-0.01 pH accuracy with unbeatable performance. Isolated 4 to 20 mA recorder output. Proportional dosing slows the pump down when the measured pH level approaches the set valve, which ensures precise dosage and avoids costly waste of chemicals due to overdosage. Alarm contact is activated whenever the pH value varies more than 2 pH units from the set point. Auxiliary contacts allow the user to attach a mixer or priming pump that is activated only when the pump is dosing. PVDF, FPM/FKM and PTFE materials are used for all parts that come into contact with liquid. Range: 0.00 to 14.00 pH, resolution: 0.01 pH, accuracy: +/-0.01 pH. Flow rate: 13.3, 11.7, 10.1, 9.0, 7.8 (LPH). Input impedance 10(12) Ohm. Dosage: proportional, acid or base, user selectable. Calibration: offset: +/-1 pH with trimmer; slope: 85 to 115 percent with trimmer. Recorder output: 4-20 mA (isolated). Dosing contact: 1 isolated contact, 2A, maximum 240V, resistive load, 1,000,000 strokes. Alarm contact 1 isolated contact, 2A, maximum 240V, resistive load, 1,000,000 strokes. Power supply: 115V +/-15 percent; 50/60Hz (40W). Environment 0 to 50 degree C; RH max 95 percent non-condensing. Measures 8-11/16" length x 5-19/32" width x 7-3/32" height.