Model 320B Flow Through pH Sensor

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CHOICE OF PVC, KYNAR¹, Teflon®, STAINLESS STEEL to handle most industrial applications. BUILT-IN PREAMPLIFIER provides reliable signal transmission. DOUBLE JUNCTION, GEL-FILLED, REFERENCE CELL provides high temperature performance, extended service life, and resists the effects of pumping, dilution and contamination. MINIMIZE FOULING PROBLEMS with large area reference junction and optional ultrasonic or flow powered cleaner.

FEATURES AND APPLICATIONS The Rosemount Analytical Model 320B pH Sensor measures the pH of a flowing aqueous fluid. Typical applications include pH monitoring or control in boiler feed water, process water, chemical processes, municipal water treatment, and many other applications. The Model 330B measures oxidation reduction potential (ORP), and has applications in chromate waste treatment, bleaching operations, chemical processes and municipal water treatment. Depending on the application, the sensor may be installed directly in the process line or in a by-pass line. The sensor consists of a flow chamber, measuring electrode, reference electrode, temperature compensator (where applicable) and an ABS junction box containing a preamplifier. These components are mounted on an ABS backplate which may be attached to a wall or, with selection of Code 30, clamped to a 2 inch pipe. The ABS plate is designed to allow quick and simple field installation of explosion-proof conduit (Code 90) or the ultrasonic cleaner (Code 08-70). See Figure 1 for outline and mounting demensions. The flow chamber contains the measuring electrode and, except for the Model 330B, an automatic temperature compensation element. The unique design electrode gland fitting allows the measuring electrode to be easily removed for maintenance or replacement. The design of this fitting prevents overtightening of the gland nut thus preserving the integrity of the O-ring process seal. The removable reference chamber includes electrolyte and a large-area liquid junction and a double junction reference electrode. The sealed reference chamber requires no pressurization, and the large supply of saturated gel solution of KNO3 electrolyte will last up to one year, in most applications, without refilling. This is especially useful for processes containing ferric chloride, sulfide (such as H2S and Na2S), cyanide, silver, lead, mercury, chlorine, sugar or ammonia. OPTIONS A number of options are available which adapt the sensor to a variety of uncommon applications. For installation in Class I, Division 2, Group D explosion-proof areas, Code 90 may be selected. Code 06 features a flow-powered cleaner, with Teflon® balls, driven by a minimum flow of 4 GPM, to impinge on the pH measuring electrode to prevent it from coating. Ultrasonic cleaning is another option for applications where the measuring electrode may become coated. The wave action retards or prevents the coating; turning a marginal application into a practical one. Codes 08-70 (Kynar flow and reference cell) specify this feature. Teflon® is a registered trademark of DuPont Films. ¹ A registered trademark of Elf Atochem North America, Inc.