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1-184 (500M) \ To J. C. Fisher AT Flemington From H. B. Carr at Flemington subject In-Process pH Analyzers Date October l6, 1969 TOcopy E. J. Hourihan C. W. Johnston F. W. Kanzler M. C. Spalding M. W. Williams (2) The Analytical Control Group has been updating files on instru mentation including laboratory and in-process types for future reference. Acting on a suggestion by M. W. Williams, literature and quotes have been requested on Process pH Analyzers. Selected pages from a Beckman Instruments bulletin and a quote (attached) indicate that this approach merits attention for the Plastisol process both from the dollar expenditure involved and the significantly improved control to be gained. The multipoint analyses possible with one pH analyzer would provide continuous measurements for control of emulsifier storage tanks, batch mix tanks, latex blend-tanks and, quite possibly, reactors. Before pursuing this approach further with Beckman and other instrument houses. Analytical Control requests comments as to the feasibility, other suggestions, practicality, etc. from the recipients of this memo. HBC:em Att H. B. Carr Note: There was an excellent article on In-Process Instrumen tation in the 10/13/69 issue of C & E NEWS. COLOR!TE 016375 \ THE APPLICATION OF pH AND ORP CONTROL SYSTEMS Many industrial applications that uti lize continuous pH/ORP monitor ing require continuous recording and/or control. The necessary com ponents required for a typical pH control system include; pH electrode station pH analyzer recorder indicating control station final control element (i.e., con trol valve or pump) These items are all available from Beckman and can be supplied as a complete, integrated control system to meet most any pH control require ment. An example of a control system is found in cooling tower water treat ment applications. Close pH control is essential so that cooling water is maintained at a balanced pH level. If the pH level is too low, excessive corrosion will result. If too high, excessive scaling will occur. If either imbalanced pH condition exists, the efficiency of heat exchangers and other process plant equipment may be seriously impaired. Complete instrumentation systems are designed by Beckman application engineers for almostjtny conceivable process pH or ORP control applica tion. Design parameters such as dead time of the system (time between the reaction and the point of measure ment), and mixing and reaction time are evaluated to insure the proper selection of system components that are best suited to a specific applica tion. 6 COLORITE 016376 BECKMAN MODEL 900 pH AND ORP ANALYZERS The Beckman Model 900 pH Ana lyzer is an analytical instrument designed to provide a continuous measure of pH in applications rang ing from food processing to water treatment. The instrument provides accurate, re liable measurements, and gives the operator a wide choice of easily selec table ranges and outputs. The Beckman Model 900 pH Ana lyzer, together with Beckman pH elec trodes, electrode chambers, and accessories, provide the world's finest system for continuous pH measure ment. The Model 900 pH Analyzer incor porates an a.c. stabilized amplifier which converts the potential between two electrodes into a signal which provides a meter indication of the pH value, and which can also drive a recorder or activate a control device. The output signal has a stability of 0.005 pH over a 24-hour period. Weather-Proof Case The case of the Model 900 is kept desiccated and sealed from moisture assuring reliable operation under the most adverse weather conditions. It may be installed in any location with out additional weather protection although a rain hood is generally con sidered good installation practice. Ambient temperature limits are --20*F to +I22`F. External Controls The standardize and function con trols are located on the outside front of the analyzer case door. Thus rou tine electrode standardization is accomplished without exposure of high impedance electronic circuitry to atmospheric conditions. These con trols are of the coin-slot type to pre vent accidental movement after adjustment. Three Mounting Choices The design of the Model 900 pH Analyzer permits it to be mounted in any of three modes. It may be panel . or surface mounted or, with an acces sory bracket, it may be mounted on either a vertical or horizontal pipe. Easy Internal Accessibility The Model 900 pH Analyzer is designed so that all components are conveniently located on the inside of the case door providing easy access for servicing, output selection, or pH range expansion. Functional circuit component boards may be removed and replaced easily, thereby minimiz ing downtime. By removing only two pins the entire door of the instrument, complete with circuitry, may be eas ily removed for repair. If operational downtime must be kept to an abso lute minimum, a spare door may be installed in a matter of minutes. Easily Read Meter The Model 900 incorporates a SVi" readout meter calibrated in 0.1 pH . units. The meter is mirror backed to eliminate parallax tl}us providing readout of the highest accuracy. Choice of Output The Model 900 pH Analyzer is avail able with either a current or potentiometric output. The current output version is designated the Model 900C. The potentiometric version is the Model 900P. An alternate potentiometric output version, the Model 900PS, provides output zero shift and variable range expansion. ORP Analysis T^wo versions of the Model 900 Ana lyzer are designed specifically for oxidation-reduction potential (ORP) measurements. One has a current out put and is designated the Model 900RC; the other has a potentio metric output and is designated the Model 900R. The physical dimen sions of the Beckman ORP and pH Analyzers are identical. Most of the external features of the Model 900 pH Analyzers are identical to those of the Model 900 ORP Analyzers. Integral Alarm /Control Option All basic versions of the Model 900 pH and ORP Analyzers are option ally available with integral set-point contacts for alarm and/or control actuation. These built-in contacts eliminate the need to mount and wire separate contact devices. Two bold, red set-point indicators are clearly visible on the calibrated indi cating meter of alarm/control ver sions of the Model 900. These indica tors are easily positioned by two sealed, coin-slotted adjustments lo cated directly beneath the meter. The upper set point is adjustable from 5 to 100% of full scale; the lower set point from 0 to 95 %. The meter indication of pH- or ORP values is completely independent of, and unaffected by, the control point settings. Each double throw relaymay be wired to provide contact closure or contact opening for operation of the set point. Complete flexibility per mits High-Low, High-High, or LowLow set point actuation. This alarm/control option is desig nated by an "A" suffix on the basic model numbers as follows: Model 900PA, Model 900PSA, Model 900CA, Model 900RA, and Model 900RCA. 8 COLORITE 0X6377 From sketches below, please check the box which most nearly approximates your proposed installation. L Measurement in Open Tank or Stream 2. Measurement in Pressurized Tank (to approx. 40 psig) f--------#--------------------------------#----------------- ij-is- 21--% s ; hr: 3. Measurement in Tank, Pressure to 100 psig 4. Measurement in Recycle Stream, Atmospheric Discharge 5. Measurement in Piped Sample Stream (Pressure to 100 psig) 6. Measurement in Main Process Pipeline (Detach Here) 7. Other (please sketch) l,J 0T>C>C<C /i'eico Lc.it tAci, ,D COLORITE 016378 BECKMAN PROCESS pH ACCESSORIES (cont'd) Electrode Switches for \ Multi-point Analysis ' The Beckman Electrode Switch per mits analysis of up to six different streams or solutions with only one pH analyzer. The switch is available in two models, the Model #74700 for automatic operation and the Model #2040 for manual operation. Each desired electrode station must be provided with a glass electrode, a reference electrode, and a thermocompensator, The electrodes are con nected to the pH analyzer through the electrode switch. The automatic switch may be used with most standard six-point recorders. It is actuated by the dis tributor switch in the recorder step ping in sequence to each electrode station. The recorder distributor switch should be of the "break before make" type, should have a dwell time of at least 20 seconds per point, and should be capable of opening and closing a 0.6 amp circuit at 7 volts a.c. A manual override on the Model #74700 allows selection of any one station for continuous analysis. The manually operated switch allows an operator to select the electrode assembly at which pH measurements are desired. The electrode assemblies may be located as far as 200 feet from the electrode switch. The gasketed and desiccated electrode switch case con tains manual standardization controls for each electrode group. Any combination of electrode cham bers may be used with either electrode switch. The selection of electrodes and electrode chambers should be compatible with solution composition and electrode station mounting requirements. 476280 Adaptor for #19565 and 419566 Reference Electrodes This adaptor kit is required for flow chamber installations utilizing either the #19565 or #19566 Reference Electrodes. The kit comprises a 200 cubic centimeter plastic reservoir with mounting bracket, tube fittings, and tubing. Model 900 Air Purge Kit The Beckman #191343 Purge Kit for Model 900 pH and ORP Analyzers is designed to meet ISA (Instrument Society of America) recommended procedure for type Z air purge. When installed, the kit is designed to reduce the classification within the enclo sure from Division 2, normally nonhazardous, to non-hazardous. Only clean, dry air or suitable inert gas may be used for the purge supply. Recommended pressure for the purge supply is 20 psig. This provide? a flow rate of approximately 4 liters per minute (8.4 cfh), and a case pressure of approximately 1 inch HA Model J Air Purge Kit The Beckman #25280 Purge Fitting is available for use with Model J Analyzers. This fitting may be easily installed in the field; or on special request, it may be installed at the factory. Model J Field Mounting Accessory The #70999 Field Mounting Acces sory, which consists of a drilled metal plate and wrap-around metal strap, allows the Model J Analyzer to be installed in a variety of locations where panel mounting would be im practical. The design of the plate per mits the Model J to.be secured either to floor flanges or to process piping. The analyzer may be mounted against a wall by using a spacer block with tjie accessory. #74700 Automatic Electrode Switch #2040 Manual Electrode Switch #76280 Adaptor Kit Field Mounting Accessory 42 COliORXTfi 016379 \ BECKMAN ELECTRODES AND ELECTRODE CHAMBERS Accurate, continuous pH monitoring begins with the proper selection of electrodes and electrode chambers. The following electrode and elec trode chamber descriptions should be used as guides to determine the most suitable combination of pH equip ment as required by installation con ditions and solution characteristics. When used in the proper combina tion, Beckman designed electrodes and electrode .chambers permit pH monitoring in almost any on-stream application. BECKMAN ELECTRODES As part of a complete pH analysis system, Beckman has designed glass and reference pH electrodes to sat isfy the rigorous requirements of continous pH measurement under the most severe industrial applications. Through years of experience in in dustrial pH, Beckman engineers have also simplified the installation, main tenance, and the selection of these electrodes. Only Beckman manufac tures electrodes which are designed specifically for the benefit of the in dustrial pH user and which incorpo rate these important features: 1. Short, compact electrode bodies are stronger than conventional . electrodes, resist breakage.They also reduce the required length and bulk of electrode chambers which facilitates installation of the pH system. 2. The wide diameter of the elec trodes not only adds strength, it . also provides the lowest possible electrical resistance in the pHsensitive bulb since the resist ance decreases as the area of the bulb increases. Lower resistance means greater sensitivity. 3. Electrode cables connect at electrode caps in a quick connect-disconnect manner. This speeds installation and fa cilitates removal for cleaning or replacement. 4. Large volume electrolyte capa cities in the reference electrodes eliminates frequent refilling, lets the pH system operate unat tended for a longer period of time. 21 COLORITE 016380 electrodes are inserted and make con tact with the sample, an electrode guard that protects the electrodes from breakage, and a reference elec trolyte reservoir assembly. Bulletin 4085 SERIES THREE pH ELECTRODE SUBMERSION ASSEMBLIES . THE ELECTRODE COVER The electrode cover protects the elec trode caps and terminals from the sample solution. A 3/& -inch NPT pipe tap is located in the top of the cover, into which the desired length of %-inch pipe (supplied by user) is threaded. The pipe not only serves as support for the submersion assembly but acts as conduit for the electrode cable and the tubing that transports electrolyte from the electrolyte reser voir to the reference electrode. The electrolyte reservoir is mounted on top of the pipe and provides head pressure on the reference electrode greater than the pressure of the liquid being analyzed. FEATURES/BENEFITS The Beckman Series Three pH Elec trode Submersion Assemblies satisfy Maximum outside diameter of 3 H the requirements of almost^ any con inches permits installation through tinuous, process pH application in much smaller openings than previ ) which pH electrodes must be sub- ously available submersion assem 1 merged in a tank, trough, flume or blies. body of water. Series Three Submer * Simplified construction permits quick assembly and disassembly for electrode cleaning, standardization, and replacement. * Available in either polyvinyl dichlo ride or stainless steel to meet the requirements of almost any pH monitoring application. sion Assemblies are available in either 1 stainless steel or polyvinyl dichloride . for use in a wide variety of chemical I applications and in a wide range of (^temperatures and pressures. The design and physical dimensions of the polyvinyl dichloride and stain less steel submersion assemblies are essentially the same. The major ele Close tolerance gland assembly with tight fitting O-ring seals insures leak- ments of each are: an electrode cover over the electrode caps and terminals, proof installation and operation. a gla|nd assembly through which the THE GLAND ASSEMBLY The heart of the Series Three Sub mersion Assembly is a gland approxi mately 2,5 inches in diameter. A glass electrode and thermocompensator each fit through holes in the gland and are sealed by O-rings in a groove part way down each bore hole, A third hole in the gland accepts a newly designed reference electrode whose diameter and overall length is the same as that of the other ele ments. The reference electrode has an electrolyte fill hole in its outer shell which, when the electrode is in place, fits between two interior sealing O-rings which form an annular spac ing ring around the electrode. This spacing ring is fed with electrolyte through a hole drilled in the body of the gland which connects to a Swagelok fitting on the top of the gland. A three-point, screw-down retainer in the center of the gland holds the three' elements in place. The gland snap fits into the cover assembly. An O-ring in a groove around the outside of the gland forms a watertight seal with the cover. COLORXTE 016381 meckman .m n A INSTRUMENTS. INC. 2900 HARBOR BOULEVARD, FULLERTON,CALIFORNIA 92634 (714) 87*1-4048; TWX 910-992-1280; TELEX 06-78413 OIVISION/OPERATION. ________________________ ISSUE POINT . One Bala Ave. Pog 1.1 Bala Cynwyd, Pa. 1900A Dote 9/10/69 Tennkco Chemicals Inc. P.0. Box 116 Burlington, S.J. 08016 Customer Inquiry YoUR INQUIRY of 8/11/69 Quotation No. 2904--0436 Attention: qty. Sr. F. Eanzler DESCRIPTION Plea** r.f.r to this Quot* No. in Future Correspondence UNIT PRICE NET PRICE 1 *1 3 11 1 1 Sodel 900C pH Analyzer 0-1A pH Output; 1-5, 4-20, 10-50 (select one). Beckman 472500 Flow Chamber Beckman 19505 Glass Electrode Beckman 19555 reference electrode Beckman 19580 Thermo compensator 150 ft. Beckman 7659A cable at *70/ FT. 12 24 HR. round chart recorder------Input (any in item one) Model 5751 (5) Mode Electronic Control Station. $710.00/ 245.00/ 31.00/ 31.00/ 45.00/ 105.00 f 300.00/EA. $520.00/EA. Thank you for your interest in Beckman Instruments and if we can BE OF ANY FURTHER ASSISTANCE, PLEASE DON'T HESITATE TO CALL US. m pjmbsal for acceptance within AO days of above date s|^nt: 2-3 wks. ABOnoM RECE|RT OF ORDER TERMS: f.o.B. FuhLERT0Nt Calif. Net SHIPPING POINT: | THE WARRANTY AND TERMS OF PAYMENT APPEARING ON THE REVERSE SIDE ARE A PART OF THIS PROPOSAL 30 Beckman' instruments.inc da ^Signed Title , Chuck Weaver____________________ Sales Representative 23-30.OS .6 COLORITE 016382