Telex 550 Headphones User Manual
Contents
1. e The measuring cell where catalytic conversion occurs e Anelectronic amplifier circuit for converting the output of the cell to a DC signal e Athermostatic assembly for temperature control in the cell compartment e Areservoir for providing make up water to the humidifier 29 Teledyne Analytical Instruments 1 1 1 Introduction Model 356 1 2 Required Equipment For proper operation the analyzer may require accessory equipment particularly in the area of sample conditioning The need for additional equipment is dictated by the conditions of each application 1 2 1 Sample Conditioning The sample must be free of entrained solids and condensable vapors and be at a relatively constant pressure between 1 and 100 psig However more efficient operation is obtained with pressures in the range of 5 to 10 psig Pressure surges can carry fluid from the humidifier into the cell and impair cell operation Filters scrubbers or pressure regulators are often necessary depending on local conditions 1 Filters If filters are necessary they should be conveniently located near the analyzer and installed in a fashion which permits easy removal for periodic cleaning or replacement Scrubbers Ifthe sample contains small quantities of acidic anhydrides 50 etc or mercaptans H S etc they will react with the electrolyte or the cathode and must be removed A caustic scrubber is usually effective Pressure regulators Whil2. Troubleshooting If there is no rise in oxygen reading when the sample flow is restarted in step 5 9 1 b the measuring cell should be checked for leaks The two most likely leaks locations are at the two terminal seal O rings or at the large ring in the cell block mounting base Check that the terminals are screwed tightly into place Frequently when a leak occurs at a terminal connection a greenish crystalline deposit will be found inside the cell around the terminal mounting screw This is lead carbonate which is formed by carbon dioxide in the air reacting with lead ions in the electrolyte If the large O ring at the mounting plate is leaking the oxygen indica tion will begin rising almost immediately after the sample flow is stopped It will continue to rise until sample flow 15 restarted at which time it will begin to gradually decrease Teledyne Analytical Instruments 5 5 Maintenance amp Troubleshooting Model 356WA Symptom No analyzer response to oxygen Cell lacks sensitivity 5 8 Teledyne Analytical Instruments g Cause Poor electrical connection or F1 fuse a standard 2 amp Slo Blo fuse has blown Cell electrolyte level too low Dirty cell Short between cell cathode and anode the screen to lead the base material is shorted If d above corrects the problem the cell has probably been poisoned probably by fluid flowing into the cell humidifier column C
3. appropriate part P N P31 To replace humidifier heater element Shut off all power and remove the AC power cord from the power source Refer to wiring diagram C 18593 left hand side bottom of the cell com partment Pull out the block assem bly from the bottom of the humidifier column pull out the heater element and unsolder the wires Replace with new heater element P N R139 Solder wires turn the terminals down into the holder and replace the holder Verify that the power switch is ON Check condition of 2A fuse Remove the compart ment cover Refer to Interconnection diagram A 18594 upper left hand corner e Connect voltmeter set to high AC to terminals 1 and 2 of terminal strip TS4 Schematic diagram D 18632 lower right hand corner Wiring diagram C 18593 upper left hand corner 5 10 Teledyne Analytical Instruments Trace Oxygen Analyzer Maintenance amp Troubleshooting 5 Symptom Cause What To Do Cell lacks sensitivity contin Faulty triac Q6 in heater Disconnect the thermo ued control or faulty triac driver A4 switch by removing one of continued the wires from TS4 terminal 3 Meter should show voltage If voltage shows short terminals 3 and 4 with a test jumper Meter reading should drop to about zero less than 10 VAC If power fails to go on and off as jumper is alter nately installed and removed between termi nals 3 and 4 the triac or tr
4. temperature somewhat above ambient so a suitable trap to remove conden sate without plugging the vent line will be required The vent line should also be arranged so that it cannot become plugged by dirt or dust 9 Teledyne Analytical Instruments 3 3 3 Installation Model 356WA 18 1 4 1 4 Female NPT 115 V 50 60 Hz Purge 7 8 dia holes Power In for 1 2 conduit Signal Out FIGURE 5 ANALYZER OUTLINE DIAGRAM Figure 5 Gas Connections to Back of Analyzer 3 4 PN Teledyne Analytical Instruments Trace Oxygen Analyzer Operations 4 Operations 4 1 Filling the Reservoir The reservoir is located on the right side of the analyzer case 1 Insure that the cap on the drain spout is securely tightened 2 Remove cap from fill port on top of reservoir 3 Pour distilled water into reservoir until it is half full about one quart The water will automatically flow into the humidifier column 4 Replace cap on fill port and securely tighten A missing or loose cap will permit the sample to vent into the analyzer case 4 2 Detector The cell is located in the heated compartment on the left side of the analyzer case as shown in Figure 4 1 To open the compartment unscrew the captive knurled knobs at the top and bottom of the compartment and remove the plastic window 4 2 1 Cell Packaging The cell is packaged separately from the analyzer It is filled with distilled water
5. Carefully remove the screw which holds the screen assembly in place Remove the screen assembly Use clean tweezers and do 5 2 Teledyne Analytical Instruments Trace Oxygen Analyzer Maintenance amp Troubleshooting 5 Cell Mounting Nuts 4 N ash Cell Block Terminal seal O rings 2 Mounting Bolts 4 Lead Electrode Cathode Screen Assembly O Ring Cover Figure 5 1 Cell Assembly 9 Teledyne Analytical Instruments 5 3 5 Maintenance amp Troubleshooting Model 356WA not touch it with your fingers Avoid any possible contamination ofthe screen c Cleanse the cell thoroughly in electrolyte solution d Insert the new lead electrode in place in the cell body and secure with lock washers and screws Carefully install screen assembly and secure with mounting screw f Immerse the cell assembly in hot cleaning solution and then rinse in distilled water g Install prepared cell assembly as described in Section 4 2 3 Installation 5 6 Screen Assembly The screen assembly will become discolored after prolonged use due to contamination When this occurs and if the cell no longer displays adequate sensitivity the entire cell assembly must be replaced Refer to Section 4 2 3 Cell Installation for cell installation instructions 5 7 Reservoir and Humidifier Column Approximately once each year the reservoir and humidifier column should be drained and cleaned Use the fol
6. NOTE Specify cell class and range of analyzer when ordering 2 O5 O ring cell terminal 1 025 O ring cell seal 1 026 O ring calibrator cover plate 2 O9 O ring humidifier column 2 8 O ring reservoir cap 2 0204 O ring flowmeter 1 A33748 Thermistor assembly 1 A3042 Humidifier column assembly 1 R2454 Humidifier column heater 110V 1 R2453 Humidifier column heater 220V 1 A5267 Reservoir cap 5 F10 Fuse 3AG 2A 5 F6 Fuse 3AG 1 4A Slo Blo 2 H2 Heater 1 B6274 Flowmeter asm specify background gas 1 B30868 PC Board Proportional temp control For applications 10 PPM or higher 1 B36026 PC Board Proportional temp control 220 1 14449 Board Proportional temp control For applications less than 10 PPM 41274 Board Proportional temp control 220 1 B29600 PC Board converter isolated O option 1 A9309 PC Board Alarm comparator dual 2 opt optional A minimum charge is applicable to spare parts orders IMPORTANT Orders for replacement parts should include the model num ber serial number and range of the analyzer for which the parts are intended A 2 Teledyne Analytical Instruments Trace Oxygen Analyzer Appendix Orders should be sent to Teledyne Analytical Instruments 16830 Chestnut Street City of Industry CA 91749 1580 Phone 626 934 1500 FAX 626 961 2538 TWX 910 584 1887 TDYANLY Web www teledyne ai com or your local representative Dra
7. a particular gas e g oxygen will depend on the relative partial pressure of that gas on each side of the leak In a sample having only a few parts per million oxygen there will be a net flow of oxygen inward unless the sample pressure is many thousands of pounds 5 9 1 Leak Detection Procedure The procedure outlined here is based on the premise that the leak rate is independent of sample flow rate a Stop the sample flow to permit oxygen to accumulate at the point of the leak b After approximately one minute restart the sample flow It is advisable to practice establishing the flow rate to 150 the reference flow indication on the flowmeter with one quick turn of the throttle valve c Simultaneous to restarting the flow start a stopwatch to measure the time required for the recorder meter to respond to the accumulated oxygen d The following are approximate times for the accumulated oxygen to reach the cell from various points in the sample path through the analyzer at 150 cc min 1 5 to 2 seconds Calibrator 3 5 to 3 75 seconds Base of humidifier column 5 5 seconds Flowmeter 6 5 seconds Metering valve 7 5 seconds Gas connection at rear of analyzer gt than 7 5 seconds Sample connection lines leading to analyzer A leak at this location may indicate a leak in the column or in the reservoir system 5 9 2 Cell Leak 5 6 Teledyne Analytical Instruments Trace Oxygen Analyzer Maintenance amp
8. cathode screens initiating an electrochemical reaction Four electrons are generated by the oxidation of the lead anode and are then used to reduce oxygen at the cathode The flow of electrons between the anode and cathode creates an electric current which is directly proportional to the oxygen concentration in the sample stream In the absence of oxygen no oxidation or reduction takes place and no current is produced In simplified form the reaction may be described as follows oxygen is reduced at the cathode by the mechanism O 2H 0 gt 40H This cathodic half reaction occurs simultaneously with the anodic half reaction Pb 20H PbO H O Ze The overall reaction is 2Pb gt 2PbO 2 2 Humidifier It is necessary to maintain a film of electrolyte on the screens of the electrode assembly This means that the humidity of the sample as it flows through the cell must be such that the water vapor pressure of the electro Teledyne Analytical Instruments 2 1 2 Operational Theory Model 356WA lyte is equal to the water vapor pressure in the sample gas If the humidity of the sample is too low water will evaporate from the electrolyte drying the cell If the sample humidity is too high water will condense out into the electrolyte flooding the cell The sample is humidified by bubbling it through water in the humidifier column just before it enters the cell humidifier column is in the s
9. to prevent oxidation of the electrodes from exposure to the atmosphere The cell should be left filled with the distilled water until the analyzer is installed and ready for operation The cell should not be exposed to the atmosphere for any prolonged duration 4 2 2 Electrolyte The cell electrolyte is Teledyne Type A used in applications where there is a complete absence of acidic anhydrides SO in the sample gas Type A electrolyte is a 10 solution w v of reagent grade potassium hydroxide KOH in distilled water Teledyne Analytical Instruments 4 1 4 Operations Model 356WA Heater Cell Compartment Terminal Strip Control Assembly 10 20 30 Interconnect Terminal Strip Span Range Humidifier Control 6 Current Adj Alarm 1 Cell Assembly Bis 123 45678 91011 12 13 14 Flowmeter Throttle Valve Sample System Humidifier Assembly Column with Assembly Reservoir Sample System Assembly Figure 4 7 Typical Model 306WA With 2 Alarm Option WARNING A electrolyte is caustic Use extreme care handling Protective equipment including but not limited to gloves and safety glasses should be worn while handling electrolyte Refer to the Material Safety Data Sheet in the Appendix regarding potential hazards and corrective action in case of accident Type B electrolyte is a 20 solution w v of potassium carbonate and should be used when t
10. 5 6 292 16 6 293 17 7 294 18 8 295 20 0 296 21 2 297 23 9 298 23 9 299 25 4 300 26 9 301 28 6 302 30 7 303 32 1 304 34 0 305 35 9 306 38 0 307 40 2 308 42 5 NOTE The MSDS on this material is available upon request through the Teledyne Environmental Health and Safety Coordinator Contact at 626 934 1592 DN Teledyne Analytical Instruments
11. ATION 2 en autre ain tete nn nier 3 1 3 2 Electrical Connections 0 00 3 1 3 3 Sample Connections 3 2 4 Operations 4 1 Filling the Reservoir 4 1 4 2 Detector Bella 4 1 4 2 1 Cell Packaging cola ee 4 1 4 2 2 rasteren are 4 1 4 2 3 Cell 4 3 4 3 Throttle Valve een 4 5 4 4 Humidity ener nn eel 4 5 ADP OWS na 4 7 4 6 Warm Up and Stabilization nennen 4 7 4 7 Calibration 4 7 5 Maintenance amp Troubleshooting 5 1 Flowmeter and Humidifier 5 1 5 2 Cell Electrolyte Level 5 1 5 3 5 1 54 VallbDralion ee 5 1 ee een 5 2 5 5 1 Electrolyte 5 2 5 5 2 Lead Electrode anna nt ss 5 2 5 6 Screen Assembly 5 4 Teledyne Analytical Instruments il Model 356WA 5 7 Reservoir and Humidifier Column 5 4 5 8 Leak Detection 5 6 5 8 1 Leak Detection Procedure 5 6 5 8 2 bide 5 7 1 anne nungen 2 Brawingikist na
12. Trace Oxygen Analyzer Model 356WA Trace Oxygen Analyzer Instruction Manual HIGHLY TOXIC AND OR FLAMMABLE LIQUIDS OR GASES MAY BE PRESENT IN THIS MONITORING SYSTEM PERSONAL PROTECTIVE EQUIPMENT MAY BE REQUIRED WHEN SERVICING THIS SYSTEM HAZARDOUS VOLTAGES EXIST ON CERTAIN COMPONENTS INTERNALLY WHICH MAY PERSIST FORA TIME EVEN AFTER THE POWER IS TURNED OFF AND DISCONNECTED ONLY AUTHORIZED PERSONNEL SHOULD CONDUCT MAINTENANCE AND OR SERVICING BEFORE CONDUCTINGANY MAINTENANCE OR SERVICING CONSULT WITH AUTHORIZED SUPERVISOR MANAGER P NM356WA 09 14 99 ECO 99 0373 Teledyne Analytical Instruments Model 356WA Copyright 1999 Teledyne Analytical Instruments All Rights Reserved No part of this manual may be reproduced transmitted transcribed stored in a retrieval system or translated into any other language or computer language in whole or in part in any form or by any means whether it be electronic mechanical magnetic optical manual or otherwise without the prior written consent of Teledyne Analytical Instruments 16830 Chestnut Street City of Industry CA 91749 1580 Warranty This equipment is sold subject to the mutual agreement that it is warranted by us free from defects of material and of construction and that our liability shall be limited to replacing or repairing at our factory without charge except for transportation or at customer plant at our option any material or construction in
13. UTION 150 cc min for the specified sample gas Excessive flow rate may cause water in the humidifier to be carried to the flowmeter causing moisture to accumulate This can cause the ball to stick in the flowmeter To remove moisture remove the flowmeter and allow to air or blow dry Refer to the detailed in structions in Figure 5 2 for removal and installation of the column 44 Humidity Control The humidity control is located on the front panel of the control unit and is adjusted to maintain a constant electrolyte level in the detector cell In effect the control governs the humidity of the sample which is directed to the cell Teledyne Analytical Instruments 4 5 4 Operations Model 356WA Outside Electrode Connected to Y Terminal Post Oxygen Generated Here Ne Electrical Terminal Board Sub Assembly Wick Saturated With KOH Electrolyte Solution Inside Electrode Connected to Terminal Post Hydrogen Generated Here Figure 8 Calibrator Assembly 4 6 Teledyne Analytical Instruments Trace Oxygen Analyzer Operations 4 1 At start up the humidity control knob should be set to 30 Note the cell electrolyte level as areference Approximately 3 32 of the bottom edge of the screen assembly should be immersed in the electrolyte 2 Operate the analyzer for 24 hours and compare the electrolyte level with the reference established in Step 1 If the level is lower than the reference
14. adjust the knob a few divisions clockwise if higher adjust a few divisions counterclockwise 3 Operate another 24 hours and repeat Step 2 4 Continue adjustments at ever increasing intervals until a constant electrolyte level is attained in the cell Once the analyzer is suitably located all components serviced and installed and sample and electrical connections made the instrument is ready for operation 45 Power When power is turned on power is applied to the cell compartment heater The cell operates without applied power but its output will vary with changes in ambient temperature 46 Warm Up and Stabilization When the analyzer is initially put into operation the air in the lines and sample passages will drive the output indication to the top of the scale The time required to sweep out this residual air may be several hours before an on scale indication is reached During this time the cell compartment is heating and reaching its controlled temperature 4 7 Calibration The analyzer is calibrated by adding a known amount of oxygen into the analyzer by means of a calibrated span gas The sensitivity of the ana lyzer is adjusted until the change indicated by the analyzer 15 equal to the amount of oxygen known to be present the span gas The span gas must be composed of the same elements as the specified sample gas 1f the analyzer s calibrated flowmeter is to be used TBE AI recommends that the oxygen content of the sp
15. ame heated compartment as the cell and so is held at the same temperature The water in the column however is cooled by evaporation into the sample gas Thus the sample gas will normally have a humidity that is too low for equilibrium with the cell It is assumed here of course that since the cell component is heated above ambient temperature the sample gas 15 less than saturated at the compartment temperature when it enters the analyzer The humidity of the sample is increased to be in equilibrium with the cell electrolyte by heating the water in the humidifier column The humidifer heater is in the base of the column and the amount of heating is adjusted with the humidity control that is located on the panel of the control unit The amount of heating required depends on the sample flow rate the sample humidity and the specific heat of the sample The correct adjust ment for the operating conditions of any particular installation is obtained by checking the cell electrolyte level periodically and replenished when neces sary according to the instructions in Section 4 2 3 Cell Installation The humidifier column also contains baffles to stop water from splas hing up into the line to the sample cell at high flow rates 2 3 Flow System The analyzer flow system is shown schematically in Figure 2 1 It includes a needle valve for adjusting the sample flow rate a flowmeter to indicate the sample flow required for calibration the humidif
16. an gas be between 70 90 of full scale on the range of interest s Teledyne Analytical Instruments 4 7 4 Operations Model 356WA 4 8 To calibrate the analyzer 1 Shut the sample gas off disconnect the sample in line and connect the the span gas to the sample inlet Allow the span gas to flow through the system Adjust the span gas flow rate until the flowmeter float is centered in the flowmeter reference indicator Note the reading of the external recorder or meter Turn the range selector switch to the range which encompases the oxygen concentration of the span gas The meter or recorder should move upscale and indicate the exact concentration of oxygen in the span gas If the external recorder meter does not indicate the proper amount of oxygen adjust the span dial until it does After the recorder or meter has stabilized on the proper readout turn off the span gas flow disconnect the span gas reconnect the sample gas and establish the proper flow Teledyne Analytical Instruments Trace Oxygen Analyzer Maintenance amp Troubleshooting 5 Maintenance amp Troubleshooting After the analyzer has been put into operation and calibration has been accomplished routine inspection will be required for normal operation 5 1 Flowmeter and Humidifier The flowmeter and humidifier column must be checked daily to insure proper flow and corrected as necessary Refer to Section 2 2 Zumidifier and 4 4 Throttl
17. anges should the instrument be moved to a higher elevation in this instance a higher span setting will be required since the sensing element is sensitive to the partial pressure of oxygen The ambient temperature does not affect the flow rate through the analyzer since the flow tube is located the same temperature controlled compartment as the cell assembly A 4 Teledyne Analytical Instruments Trace Oxygen Analyzer Appendix When span gases are used or when sample gas is being analyzed the flow can vary 10 20 and more without changing the reading It is best however to keep the sample flow so that the float in the flow tube is at or near the center of the target Otherwise a different humidifier setting may be required If positioning the float in the center of the target is in error by plus or minus one quarter of the float s diameter an error of approximately 1 5 of reading will be produced There are instances when it will be necessary to reset or check the exit flow of sample gas and set or reset the position of the target on the flow tube e When a different background gas is being analyzed When the target has been accidently repositioned on the flow tube The vent flow should be measured either with a volume displacement flow device e g a bubble o meter or a calibrated rotometer with correc tion factors for ambient temperature and pressure and sample gas density and viscosity When usin
18. any alarm or control system installed must be tested and understood both as they operate and as they can be defeated Any safeguards required such as locks labels or redundancy must be provided by the user or specifically requested of Teledyne The purchaser must be aware of the hazardous conditions inherent in the process es he uses He is responsible for training his personnel for providing hazard warning methods and instrumentation per the appropriate standards and for ensuring that hazard warning devices and instrumentation are maintained and operated properly Teledyne Analytical Instruments the manufacturer of this instrument cannot accept responsibility for conditions beyond its knowledge and control No statement expressed or implied by this document or any information disseminated by the manufacturer or his agents is to be construed as a warranty of adequate safety control under the user s process conditions Teledyne Analytical Instruments Trace Oxygen Analyzer Table of Contents 1 Introduction 1 1 Method of Operation 1 1 1 2 Required Equipment 1 2 1 2 1 Sample Conditioning 1 2 1 2 2 Recorder Meter Readout 1 2 2 Operational Theory 2 Sensor tiennie meren etterende Le 2 1 2 2 2 1 2 3 ass 2 2 3 Installation 3 1 LOC
19. e Valve 5 2 Cell Electrolyte Level The level of electrolyte in the cell must be checked daily and adjusted as necessary Refer to Section 4 2 3 Cell Installation The proper level for the electrolyte is when the bottom edge of the sensor screen is wetted but not immersed Approximately 32 of the silver electrode should extend into the pool of electrolyte 5 3 Reservoir The water level in the reservoir should be checked at least every two weeks Follow this procedure a Remove the cap from the filler spout b Obtain a clean glass tube about 4 to 5 inches long and about 4 outer diameter Lower the tube into the tank through the filler spout until it touches bottom d Place finger over the end of the tube and withdraw the tube from the tank The height of water in the tube is the height of the water level in the tank If the water level in the reservoir is below 1 add a quart of distilled water f Replace the filler spout cap securely after verifying that the ring seal is in good condition Teledyne Analytical Instruments 5 1 5 Maintenance amp Troubleshooting Model 356WA 5 4 Calibration The sensitivity of the unit should be checked at two to four week intervals Calibration procedures are described in Section 4 7 Calibration 5 5 Cell The electrochemical reaction in the analytical process results in the accumulation of lead ions in the electrolyte making the replacement of the lead e
20. e the analyzer will accept pressures to 100 psig a range of 5 to 10 psig is recommended In addition pressure surges can affect instrument operation In either case the use of a pressure regulator is advisable Install the regulator as close to the sample point as possible to reduce sample travel time to a minimium The regulator should incorporate a metallic diaphragm to prevent the diffusion of atmospheric oxygen into the sample 1 2 2 Recorder Meter Readout The meter installed on the 356WA is either analog or digital The recorder used for analyzer signal readout is usually of the self balancing potentiometric type It should have an input inpedance of 10 Q or higher Output is 0 to 1VDC or less optional 1 to 5 4 to 20 10 to 50 mADC 1 2 s Teledyne Analytical Instruments Trace Oxygen Analyzer Operational Theory 2 Operational Theory 2 1 Sensor The sensor is an open cathode cell an electrochemical transducer specific to oxygen The cathode of the cell is composed of silver screen elements with a large surface area The screen assembly is mounted in an acrylic block with the lower edges of the screens immersed in potassium hydroxide electrolyte A thin layer of electrolyte is maintained on the sur faces of the screens by capillary action A lead disk is positioned under the screens and serves as the anode An exploded view of the cell is showm in Figure 5 1 The sample gas stream is passed directly over the
21. ell has been poisoned by a component in the sample Cell electrolyte level too low due to misadjusted or faulty humidity control Cell electrolyte too high due to misadjusted or faulty humidity control Faulty humidity control What To Do Verify proper connection from the cell through the control unit to the external recorder or meter check for blown fuse Replace as necessary Inspect electrolyte level and add as necessary See Section 4 2 3 item 4 Remove cell and clean thoroughly See Section 4 2 3 Correct short Refill with fresh electrolyte as needed Check for excessive flow rate Check for excessive foam ing in the humidifier column Drain and clean reservoir as necessary Refer to Section 5 8 If there has been no change in the normal sample composition a scrubber may be required to remove the offending component Add electrolyte as neces sary Adjust humidity control See Section 4 5 Drain electrolyte and refill Adjust humidity control See Section 4 5 Shut off main power Disconnect orange wire from TS1 terminal 5 place a voltmeter set to AC current range 0 100 mA in series with TS1 5 and the disconnected orange wire CAUTION High voltage AC present Trace Oxygen Analyzer Maintenance amp Troubleshooting 5 Symptom Cause What To Do Cell lacks sensitivity contin Faulty humidity control contin Turn humidifier control ued ued completely counter c
22. g a volume displacement flow device it will be necessary to correct the 150 cc min flow rate for ambient temperature and pressure It will also be necessary using either type of flow measuring device to compensate for the increase in flowrate due to humidifying the sample gas The flow tube inside the analyzer is measuring the dry gas flowrate To determine the corrected vent flow rate it will be necessary to know the ambient temperature in K the ambient pressure in mm Hg and the vapor pressure of water at ambient temperature Ambient temperature can be measured in Centigrade or F and con verted to K Degrees 5 F 32 9 Degrees C 273 Ambient pressure can be measured with an accurate barometer If the actual oxygen concentration were for example 8 0 ppm the resultant reading would be 7 9 float high or 8 1 float low Teledyne Analytical Instruments A 5 Appendix Model 356WA or by knowing the altitude P mm Hg 760 2 50 per 100 ft of altitude The vapor pressure of water at ambient temperature can be obtained from Table 1 To determine the corrected flow F substitute the ambient tem perature pressure vapor pressure of water the following formula corrected 150 x T 760 mm 294 Where T ambient temperature in K P ambient pressure in mm Hg P ae Vapor pressure of water at ambient te
23. he CO level in the background gas is between 500 ppm and 1 This narrow range is rarely encountered It is however available from the factory Safety related information for this electrolyte can be found in the Appendix Type C electrolyte is a 20 solution w v of potassium bicarbonate and should be used when the CO level in the background gas is between 1 and 100 Safety related information for this electrolyte can be found in the Appendix 4 2 Teledyne Analytical Instruments Trace Oxygen Analyzer Operations 4 Sufficient electrolyte is provided for initial servicing of the cell Elec trolyte for future service should be ordered from Teledyne When ordering specify type and quantity 4 2 3 Cell Installation Prior to servicing and installing the cell inspect the lead electrode in the acrylic base for signs of oxidation indicated by a reddish brown or yellow discoloration If discoloration is noted clean the cell as directed in section 5 5 2 before placing it in service WARNING Type electrolyte is caustic Use extreme care in D 2 3 4 handling Protective equipment including but not limited to gloves and safety glasses should be worn while handling electrolyte Refer to the Material Safety Data Sheet in the Appendix regarding potential hazards and corrective action in case of accident Remove the four cell mounting bolts which secure the plastic cover Pour out the distilled water Po
24. iac driver is probably at fault and should be replaced If power does on off the thermoswitch P N T22 is faulty and should be replaced If none of the above improve the sensitivity replace the cell Teledyne Analytical Instruments 5 11 5 Maintenance amp Troubleshooting Model 356WA 5 12 Teledyne Analytical Instruments Trace Oxygen Analyzer Appendix Appendix Specifications Standard Ranges Three ranges between 0 10 PPM and 0 5000 PPM O 0 2 PPM O avail able as an option SamplingSystem Wetted parts 304 welded stainless steel Sensitivity 1 of low range Accuracy 2 of low range Response and Recovery Time 90 in less than 1 minute for lowest range Operating Temperature Range 40 F to 120 F 5 C to 49 C Sample Requirement Flow 150cc min Pressure 1 to 150 psig Temperature 60 F to 100 F 15 C to 38 C Power Requirement 115 VAC 50 60 Hz 150 W other voltages available Alarms Adjustable single or dual alarm op tional setpoints Recorder Signal Output Voltage 0 1 VDC or less Current 1 5 4 20 10 50 mADC optional Local Readout Digital or analog meter Specified flow rate required only during calibration Measuring cell is not sensitive to changes in flow rate Teledyne Analytical Instruments A 1 Appendix Model 356WA Spare Parts List QTY PART NO DESCRIPTION 1 B1473 Lead electrode 1 C1372 Cellassembly
25. ic pressure A s female NPT fitting is installed on the back of the instrument for making sample and vent line connections Thepurge line is fitted with a 4 tube fitting 1 Connectors Use straight tube connectors where possible This facilitates removal of the analyzer section from the case during maintenance or service 2 Lines Lines should consist of metallic tubing since oxygen can diffuse through plastic Use continuous tubing where possible 3 Vent The analyzed sample is vented through the back of the unit as shown in Figure 2 3 3 2 9 Teledyne Analytical Instruments Output GND Current Output Trace Oxygen Analyzer Installation 3 HOT AC Power In NEUT 150 Watt Max GND Load NO Alarm 2 NC NO Alarm 1 NC Figure 2 2 General Connection Diagram See the specific Interconnection Diagram for your instrument in the drawing package located at the back of the manual See also any Addenda that may be Included with this manual The analyzer should have a vent line of 44 diameter tubing at least two feet long running downward from the vent connection This is to prevent air from diffusing into the reservoir and dissolving into the humidifier make up water If it is not desirable to vent the sample into the atmosphere a vent line to carry the sample to a suitable venting area will be required The sample leaves the vent connection of the analyzer saturated with water vapor ata
26. ier the measur ing cell and an automatic level control system for the water in the humidi fier As can be seen from Figure 2 1 the sample enters the humidifier column against the pressure of a water column from the base of the humidi fier to the water level in the reservoir which is approximately 4 inches This determines the minimum sample pressure at which any sample can flow through the analyzer In practice the sample pressure must be somewhat greater than this in order to have an adequate flow rate The automatic level control in the humidifier column is accomplished by connecting the sample outflow from the cell to the bottom of the reser 2 2 Teledyne Analytical Instruments Flowmeter Sample In gt Throttle Valve Trace Oxygen Analyzer Operational Theory 2 Humidifier Column Cell Pressure ATM b a Reservoir L Drain Cell Compartment Figure 2 7 Flow System Schematic 9 Teledyne Analytical Instruments 2 3 2 Operational Theory Model 356WA voir This places a back pressure on the sample in the cell and upper portion of the humidifier column equal to the water column from the bottom of the reservoir to the water level in the reservoir Thus the water level in the humidifier column is held even with the sample connection at the bottom of the reservoir There will be a slight additional pressure in the top of the humidifier column depending on
27. l Strip No 4 LIS Cu Sample Flow Control Valve Cell Block Humidifier Column Heater Humidifier Column Figure 4 2 Cell Compartment Components 4 4 Teledyne Analytical Instruments Trace Oxygen Analyzer Operations 4 6 Connect the red lead to the center terminal and the black lead to the outer terminal NOTE The silver screens in the cell have been specially treated to pro vide proper detection characteristics They must be kept clean and MUST NOT be touched Even clean fingers secrete natural oils which contaminate the screens If the screens need straightening wash a small pair of tweezers thoroughly to remove any grease rinse them in distilled water and use them to carefully bend the screens back into place 4 3 Throttle Valve The throttle valve is located at the top of the reservoir tank Refer to Figure 4 1 1 Gently turn the valve counterclockwise A stream of bubbles should appear at the base of the humidifier column and the float of the flowmeter should rise in its tube 2 Adjust the valve so that the flowmeter float is centered in the CAUTION flow rate reference indicator Open the throttle valve carefully Excessive flow rate may cause water in the humidifier column to be carried into the detector cell This can cause erratic readings and may require disassembly cleaning and refilling of the sensor 3 The flowmeter indicator has been factory set to a flow rate of CA
28. lectrode or the electrolyte necessary 5 5 1 Electrolyte Replacement Replace the electrolyte at least every two months or even more fre quently if foreign matter is accumulating in the cell Remove the cell from is compartment and drain clean rinse and refill as described in Section 4 2 3 Cell Installation After the cell is serviced or replaced calibrate the analyzer as outlined in Section 4 7 Calibration 5 5 2 Lead Electrode If electrode is discolored when new or has obviously deteriorated from use it may be necessary to clean or replace the electrode Use the following procedure while referring to Figure 5 1 If the lead electrode is simply discolored clean the entire cell according to the following procedure a Heat a quart of Teledyne cleaning solution to slightly below the boiling point and completely fill the cell cavity with the heated solution Let the solution stand for approximately five minutes Drain and dispose of solution in an approved manner Repeat steps a and b d Rinse the cell with distilled water and then fill with electrolyte Let stand for approximately two minutes and then drain and dispose of electrolyte in an approved manner Refill the cell with electrolyte immersing the lower edge of the silver screens to about a 3 32 depth If the lead electrode is obviously beyond repair it must be replaced a Remove the terminal nuts by removing them from the mounting screws b
29. lockwise Turn on main power While watching the voltmeter turn the humidifier control clock wise the meter reading should go from 0 50 milliamps If not replace the humidifier heater element or the humidifier heater control To deter mine which should be replaced see paragraph below If there is no current either the humidifier element or control is defective To determine which it is Turn the humidifier control knob fully cew Disconnect the voltmeter from TS1 5 and orange wire Reconnect the orange wire Change the voltmeter function to 200V Place the voltmeter across TS1 5 and termi nal TS1 4 Watching the meter turn the humidifier control knob cw and watch the voltmeter read 0 110 to 120V AC If not replace R2 behind the control knob see paragraph below If there is voltage replace the heater element see paragraph below Teledyne Analytical Instruments 5 9 5 Maintenance amp Troubleshooting Symptom Cause Cell lacks sensitivity contin Faulty humidity control contin d Cell compartment not at d proper temperature 120 F e Faulty triac Q6 in heater e control or faulty triac driver A4 Model 356WA What To Do To replace humidifier control Shut off all power and remove the AC power cord from the power source Refer to wiring diagram D 18633 upper right hand corner of the control unit Remove the wiring and controls Replace R2 with
30. lowing procedure a Reduce sample flow to approximately 50 cc min b Refer to Figure 4 1 Place a small funnel with attached tubing beneath the drain spout which 15 located on the underside of the reservoir Remove the drain spout cap and allow the reservoir and humidifier column to drain thoroughly c Replace the drain spout cap turn the sample flow off and remove the fill cap on the top of the reservoir Add a small amount of electrolyte to a pint of warm distilled water Pour the solution into the reservoir and replace the fill e Gently open the throttle valve and permit the sample to flow for five to ten minutes f Reduce the sample flow to 50 ec min and drain the solution from the reservoir When drained replace the drain cap and turn off the sample flow g Rinse by filling with distilled water and draining several times h If the humidifier column still retains deposits on its walls it should be removed and cleaned with a brush and suitable cleaner See 9 Teledyne Analytical Instruments Trace Oxygen Analyzer Maintenance amp Troubleshooting 5 Figure 5 2 After cleaning thoroughly rinse the column in distilled water before reinstalling NOTE felecirolyte has severely etched the column It should be replaced i After the reservoir and column have been cleaned refill the reservoir as outlined in Section 4 1 Filling the Reservoir Removing the Humidifier Column 1 Grasp the
31. mp in mm Hg By way of example suppose that the target s position on the flow tube is in question and it has been determined that the ambient temperature is 77 F and the altitude where the instrument is being used is 5000 ft above sea level Ambient Temp K 57 32 273 298 K Ambient Pressure P mm Hg 760 2 50 50 635 mm Hg Vapor Pressure of Water at 298 K 23 9 mm Hg Corrected Flow 150x 298 X 760 a corr 189 lt 294 635 This approximation is within 0 5 of the ICAO Standard Atmo sphere over the range 0 7500 ft above sea level Ref Fluid Mechanics for Engineering Technology by Irving Granet Prentice Hall pp 83 84 Reference ambient temperature 294 K 21 C was the ambient temperature used in the Faradaic calculations A 6 Teledyne Analytical Instruments Trace Oxygen Analyzer Appendix From these computations the exit flow rate should be set to 189 cc min using an appropriate flow measuring device and the target respositioned if necessary so that the float is centered within the target opening Subsequently it should not be necessary to measure the exit flow unless another circumstance of the type listed above occurs Teledyne Analytical Instruments A 7 Appendix Model 356WA Table 1 Vapor Pressure of Water From 288 308 K Ambient Temperature K Vapor Pressure of Water mm Hg 288 12 9 289 13 7 290 14 6 291 1
32. nce of sample lines and power NOTE Since the level of the electrolyte in the measuring cell is critical and the water level control system for the humidifier is gravity sensitive THE ANALYZER MUST BE MOUNTED SO THAT THE BOTTOM OF THE CASE IS LEVEL 3 2 Electrical Connections A diagram of the necessary electrical connections is shown in Figure 2 2 Note See the Interconnection Diagram drawing A 37526 included in the back of this manual as well as any Addenda that may be included with this manual for information specific to your instrument Teledyne Analytical Instruments 3 1 3 Installation Model 356WA Percent Oxygen Sample Line Recorder Signal Leads Analyzer 1 4 or 1 8 Metal Tubing 22 ga Twisted Pair Shielded Cable Pressure Shut Off Regulator Valve 5 10 psig Output Sample 115 VAC Power and Ground 2 Power Leads 1 Ground Wire 16 Insulated Condensate Trap Figure 2 1 Typical System Layout The connections include a terminal for grounding the analyzer case and chassis in accordance with accepted industrial practices The maximum power requirement is less than 112 amperes at 115 VAC 3 3 Sample Connections The sample line is connected at the back of the analyzer case as de picted Figure 2 3 Use care in assembling any part of the sampling system to avoid leaks Oxygen can diffuse into the system through small leaks even when sample pressure is much greater than atmospher
33. sse 3 Calibration Data a ae 4 Material Safety Data A 9 Teledyne Analytical Instruments Trace Oxygen Analyzer Introduction 1 Introduction The Teledyne Analytical Instruments Model 356WA Trace Oxygen Analyzer is designed to detect oxygen concentrations in process streams It utilizes Teledyne s patented electrochemical sensor which requires minimal maintenance and exhibits a 90 response in less than one minute Cell output is insensitive to flow rate changes within the operating range of the analyzer sflowmeter The Model 356WA features a welded stainless sampling system for long term leak free operation While the analyzer is offered in several configurations they are virtually identical with the exception of housing or options such as special meters For purposes of clarity this manual will discuss the unit in general The differ ences between the configurations are minor and will be obvious to the user 1 1 Method of Operation Gas from the process stream is fed through a sample line to the sample inlet port of the analyzer The sample is directed through the analyzer s sample system where oxygen concentration is detected by the sensor The sensor generates an output signal which is read out on a suitable recorder or meter The analyzer components include e throttle valve and flowmeter to control sample flow e A humidifier to condition the sample
34. the flow rate the pressure needed to push the sample through the cell and associated tubing but at normal flow rates this merely slightly lowers the level in the humidifier column The sample bubbles through the water in the reservoir on its way to the outlet port Some of the water vapor will re condense so that the sample flows out of the outlet port saturated at the reservoir temperature which is slightly above ambient The sample bubbling through the make up water will scrub out any oxygen which may be dissolved in it This assures that the sample will not pick up any oxygen as it passes through the humidifier column Teledyne Analytical Instruments Trace Oxygen Analyzer Installation 3 Installation 3 1 Location With proper shielding of the leads the analyzer and the readout device can be separated by as much as 1 000 feet However they should be placed as close together as possible For the most convenient operation the read out recorder or meter should be within view of the controls particularly when the unit is being calibrated Figure 2 1 depicts a typical system layout Other location considerations 1 The analyzer should be sheltered from the elements 2 Ambient temperature must be within 30 to 120 F 3 The unit should not be subject to excessive shock or vibration 4 Itshould be as close as possible to the sample point 5 There must be access to the back and side of the unit for connection or maintena
35. tube and with a twisting motion work it up into the top humidifier block until it clears the bottom block completely 2 Angle the bottom of the tube towards you and twist it free of the top block 3 The top and bottom O rings will remain captive in their blocks To Reinstall 1 Engage the top of the tube in the top block at an angle and twist up into the cavity of the top block unit the bottom of the tube clears the bottom block 2 Swing the tube into line and twist down into the bottom block until the tube seats NOTE 77 flowmeter is similarly constructed and can be removed and reinstalled following the same procedure outlined above Figure 5 2 Removing Replacing the Humidifier Refer to the Spare Parts List in the Appen dix for replacement part numbers for the 9 Teledyne Analytical Instruments 5 5 5 Maintenance amp Troubleshooting Model 356WA flowmeter column or humidifier column 5 9 Leak Detection The most frequent cause of trouble in trace measurement is leakage Tiny leaks which may be unnoticeable can cause serious errors in trace measurements One of the principal problems is that air can diffuse into a gas line through a small leak even though the gas pressure in the line may greatly exceed atmospheric pressure When a leak occurs in a system where the mass flow velocity is less than the molecular velocity gas molecules move in both directions through the leak The net flow of
36. ur about half the furnished electrolyte into the cell and slosh until all components within the cell are wetted by the solution Drain and dispose of the solution Wipe the top of the cell and the with a clean disposable tissue to remove solution from the exterior DO NOT touch the interior of the cell Carefully pour in electrolyte until it just touches the bottom edge of the silver screen assembly at all points This 15 indicated by definite wicking of electrolyte onto the screen assembly at every point along ithe bottom edge It is essential at this point that the bottom edge of the screen assembly be wetted at all points as seen by the wicking action but not over immersed as large a surface area as possible of the screen assembly must remain above the electrolyte while every point of the bottom edge must be wetted The level is correct when the bottom edge of the sensor screen is wetted but not immersed approximately 7 52 of the silver electrode extends into the pool of eelectrolyte NOTE The electrolyte level in the cell is critically related to its sensitivity due to the change in the cathode surface area exposed to the eledctrolyte 5 Carefully place the cell under the cell mounting plate with the outer terminal toward the front Secure in place with four bolts supplied with the cell Refer to Figure 4 2 Teledyne Analytical Instruments 4 3 4 Operations Model 356WA Cell Mounting Bolts Termina
37. which defects become apparent within one year from the date of sale except in cases where quotations or acknowledgements provide for a shorter period Components manufactured by others bear the warranty of their manufacturer This warranty does not cover defects caused by wear accident misuse or neglect We assume no liability for direct or indirect damages of any kind and the purchaser by the acceptance of the equipment will assume all liability for any damage which may result from its use or misuse We reserve the right to employ any suitable material in the manufacture of our apparatus and to make any alterations in the dimensions shape or weight of any parts in so far as such alterations do not adversely affect our warranty Important Notice This instrument is intended to be used a tool to gather valuable data The informa tion provided by the instrument may assist the user in eliminating potential hazards caused by the process that the instrument is intended to monitor however it is essential that all personnel involved in the use of the instrument or its interface with the process being measured be properly trained in the process itself as well as all instrumentation related to it The safety of personnel is ultimately the responsibility of those who control process conditions While this instrument may be able to provide early warning of imminent danger it has no control over process conditions and can be misused In particular
38. wing List 5855 47143 D 47142 B 30364 B 14718 B 15016 D 22297 D 47139 B 21916 Outline Piping Schematic Schematic Schematic Schematic Wiring Wiring Interconnection Teledyne Analytical Instruments A 3 Appendix Model 356WA Calibration Data Range The ranges of this analyzer are Range Switch Position No 1 PPM O Range Switch Position No 2 Range Switch Position No 3 PPM Output Signal The output signal is D C Background Gas This analyzer is intended to measure oxygen in a background of The flowmeter has been set to indicate a flow of 150 cc min of this gas If any other type of gas is to be analyzed the flowmeter must be reset for that gas using a displacement type flowmeter when the flow 15 set to 150 cc min Cell Class Electrolyte Type Type A 10 potassium hydroxide in distilled water Type B 10 potassium carbonate in distilled water Type C 20 potassium bicarbonate in distilled water Calibration Considerations In order to calibrate the Model 356 all that is required is to center the float of the flow tube in the target add a known quantity of oxygen 0 100 PPM via a calibrated span gas and adjust the span potentiometer to match the known oxygen concentration of the span gas It should not be necessary to compensate for changes in altitude or ambient temperature The flow tube is a mass flow device and therefore automatically com pensates for altitude ch
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