Panametrics CGA 351 User Manual Download Page 75

Page: 75 / 119

CGA 351 User’s Manual

Chapter 5.

Chapter 5.

5.1 Service and Maintenance

5.1.1

Introduction

The CGA 351 has been designed to provide years of trouble-free operation. However, because of the technical

challenges involved in measuring very low levels of oxygen, some difficulties may occasionally be encountered. The

procedures for resolving many of these situations are discussed in this chapter. If the information provided in this

chapter is insufficient to solve the problem, please contact the factory for further assistance.
If a faulty component is discovered in the CGA 351, that component is usually replaceable on site. Contact the factory

to obtain a new part, and proceed to the appropriate section of this chapter for installation instructions.

WARNING!

To ensure safe operation of the CGA 351, it must be installed and operated as described in this

manual.

In addition, be sure to follow all applicable local safety codes and regulations for installing electrical

equipment. In addition, all procedures should be performed by

trained service personnel.

5.1.2

General Troubleshooting

This section discusses the following general categories of problems that may arise with the CGA 351:
•

faulty wiring

•

a faulty thermocouple

•

a faulty oxygen sensor

•

a faulty sensor furnace

• missing sensor furnace voltage

Use this section to troubleshoot any malfunction in the CGA 351. Refer to Figure 5 on page 87, and complete the

following sections in the sequence indicated.

Note:

For information regarding component locations and/or wiring connections in an optional enclosure, see

Appendix C.

Summary of Contents for CGA 351

Page 1: ...panametrics com Flow 910 199 Rev D Aug 2021 CGA 351 Zirconium Oxide Oxygen Analyzer User s Manual...

Page 2: ......

Page 3: ...rpose and warranties arising from course of dealing or usage or trade Return Policy If a Panametrics Sensing Inc instrument malfunctions within the warranty period the following procedure must be comp...

Page 4: ...Warranty 4 CGA 351 User s Manual no content intended for this page...

Page 5: ...r 4 4 1 Setup and Calibration 27 4 1 1 Introduction 27 4 1 2 Accessing the User Program 27 4 1 3 The Cal Menu 27 4 1 4 Setting Up the Alarm Relays 28 4 1 5 Setting the Temperature Controls 34 4 1 6 Au...

Page 6: ...tions 93 A 1 3 The CGA 351 Nernst Equation 94 Appendix B B 1 CE Mark Compliance 97 B 1 1 Overview 97 B 1 2 EMC Compliance 97 B 1 3 LVD Compliance 97 Appendix C C 1 Optional Enclosures 99 C 1 1 Introdu...

Page 7: ...nclosure which contains the oxygen sensor sensor furnace thermocouple inlet port with needle valve outlet port with flowmeter and interconnecting cable s and an electronics enclosure which contains th...

Page 8: ...ture of the oxygen sensor and the sample gas an inlet needle valve and an outlet flowmeter adjust the sample gas flow to 400 40 cc min Figure 2 Sensor Enclosure Flowmeter Furnace Bracket Flowmeter The...

Page 9: ...pressure gauges by pass loops and sample pumps It is recommended that stainless steel construction be used for all wetted parts of the sample system A typical sample system is shown in Figure 3 below...

Page 10: ...operation of the oxygen sensor Also ambient air is the usual reference gas on the outside of the zirconium oxide sensor The sensor furnace also generates the convective flow that circulates the sample...

Page 11: ...ge at the electrodes The cell voltage rises logarithmically as the amount of oxygen in the sample gas falls allowing the accurate measurement of very low levels of excess oxygen 1 1 6 The Heater Contr...

Page 12: ...y Note A third parameter Derivative Action is not used with the CGA 351 The heater control circuit is configured at the factory for optimum performance Because of the strong interaction between the pa...

Page 13: ...irectly accessible and located within 1 8 m 6 ft of the unit WARNING Power up the CGA 351 as quickly as possible after introduction of the sample gas If the analyzer is left installed without power th...

Page 14: ...s are suitable for the environmental conditions at the installation site the analyzer system will be installed in a location with little or no vibration the ambient temperature at the installation sit...

Page 15: ...es are in a vertical position with the inlet outlet connectors on the bottom 4 The flowmeter which is fastened to the right side of the sensor enclosure is connected to the discharge port on the botto...

Page 16: ...vice personnel To access the terminal printed circuit board remove the cover below the digital display panel which is fastened with six 6 Phillips head screws The PC Board has terminal blocks TB1 12 c...

Page 17: ...to terminal block TB2 as follows a Connect the positive sensor wire white 1 to pin b Connect the negative sensor wire white 2 to pin 2 Locate the leads from the thermocouple Connect these leads to ter...

Page 18: ...ower conductors to an entry port on the bottom of the electronics enclosure CAUTION Be sure that the input voltage to the CGA 351 complies with the value specified at the time of purchase If the volta...

Page 19: ...1 3 1 2 89 6 3 4 171 7 3 8 187 6 3 8 162 SIDE VIEW FRONT VIEW 16 406 14 1 4 362 7 8 22 7 8 22 8 1 4 208 3 7 8 98 15 1 4 387 17 432 1 2 12 7 4pl Mounting Hole Mounting Note Dimensions are in inches mil...

Page 20: ...e Mode TB1 OUTPUTS HEATER TC Thermocouple Furnace Any Gnd Shield 1 2 Furnace G G Any Gnd Shield Thermocouple O2 Group Description TB2 INPUTS Pin Sensor Sensor ALL ALL 6 White 5 White N A G White N A R...

Page 21: ...3 months thereafter see Calibrating the CGA 351 on page 62 Never use thread sealant on any connection in the sample gas flow path Thread sealant gives off combustible vapors that can cause reading err...

Page 22: ...us is gained by pressing the ESC ENT and ESC keys in sequence Then a password must be entered The default password is 2719 General locked access to these submenus is gained by pressing the ESC ENT and...

Page 23: ...r the User Program by pressing the ESC key and proceed as follows IMPORTANT In some applications portions of the User Program may be locked to prevent end user access If this is the case entrance to t...

Page 24: ...y selected Simply press ENTER Notice that the Disp option is grayed out at this time POWER ESC ENTER Table 6 Cfg Cal Opt Disp To proceed with the 1 Cfg option press ENTER To abort the operation press...

Page 25: ...sk appears to its left 3 When all of the desired outputs have been selected use the and keys to select OK and press the ENTER key Notice that the newly configured display shows the slot number and the...

Page 26: ...t values listed in Table 64 on page 43 consider a situation where the current oxygen reading is 7 5 The Auto Range feature would select the current active range as Range 3 in the table Then This means...

Page 27: ...r Program the Cfg option is already selected Simply press ENTER POWER ESC ENTER Table 12 Cfg Cal Opt Disp To proceed with the 1 Cfg option press ENTER 1 Cfg POWER ESC ENTER Table 13 From 1 Cfg A list...

Page 28: ...4 of the User s Manual as required for detailed programming instructions for the analog output unit type ARng zero set point 0 span set point 100 When configured as specified above the 4 20 mA analog...

Page 29: ...aking changes in the User Program while data is being displayed If the currently selected display input is accidentally deselected the screen reverts to the following Although the meter is still colle...

Page 30: ...endix A The Nernst Equation for details on performing such calculations 3 1 7 Powering Down When it becomes necessary to power down the CGA 351 for service proceed as follows 1 Press the POWER button...

Page 31: ...Below Normal Trip Reset Non Fail Safe Fail Safe 1 Cfg Sensor Temperature Oxygen CJC Temp Duty Cycle 0 Fault Alarm 0 Display 2 Alarm 1 2 Alarm 2 ARng AR A deg C deg F mV deg C deg F pcnt Disp as selec...

Page 32: ...CGA 351 User s Manual 26...

Page 33: ...oper setup and calibration of the CGA 351 4 1 2 Accessing the User Program To ensure accurate oxygen level readings and to make use of the alarm relays serial port and analog output the appropriate en...

Page 34: ...list box The following alarm features may be set in this submenu Table 23 Cfg Cal Opt Disp Use the and keys to select 2 Cal and press ENTER 1 Cal 2 Cal POWER ESC ENTER Table 24 Setup Use the and keys...

Page 35: ...The setup of Alarm 1 is used as an example in this manual To set up Alarm 2 3 or 4 return to the previous prompt and select the desired option Then repeat the following steps 4 1 4 1 Setting the Trip...

Page 36: ...press ESC until you exit the User Program or proceed to the appropriate section to continue setting up the alarms Table 29 Alarms Alarm Feat Use the and keys to select Trip Value and press ENTER Trip...

Page 37: ...y returns to the Alarm Features prompt Either press ESC until you exit the User Program or proceed to the appropriate section to continue setting up the alarms Table 31 Alarms Alarm Feat Use the and k...

Page 38: ...t value IMPORTANT Always return the alarm relay to this state at the conclusion of the testing Trip manually triggers the alarm relay to its ON state Reset manually returns the alarm relay to its OFF...

Page 39: ...during normal operation and is de energized when the trip point is crossed In normal non fail safe operation the alarm relay is energized only when the trip point is crossed The meter now automatical...

Page 40: ...ese settings without specific instructions from the factory Proceed to the appropriate sub section to program the desired temperature control feature Table 37 Cfg Cal Opt Disp Use the and keys to sele...

Page 41: ...d to the appropriate section to continue setting up the temperature control Table 40 Temp Cntrl Use the and keys to select Setpoint and press ENTER Setpoint Sensor Temp Air Offset POWER ESC ENTER Tabl...

Page 42: ...ram or proceed to the appropriate section to continue setting up the temperature control Table 44 Temp Cntrl Use the and keys to select Sensor Temp and press ENTER Setpoint Sensor Temp Air Offset POWE...

Page 43: ...rns to the Temp Control prompt Either press ESC until you exit the User Program or proceed to the appropriate section to continue setting up the temperature control Table 47 Temp Cntrl Use the and key...

Page 44: ...re also available in the above list box The meter now automatically returns to the Temp Control prompt Either press ESC until you exit the User Program or proceed to the appropriate section to continu...

Page 45: ...tional band The meter now automatically returns to the Temp Control prompt Either press ESC until you exit the User Program or proceed to the appropriate section to continue setting up the temperature...

Page 46: ...ation time The meter now automatically returns to the Temp Control prompt Either press ESC until you exit the User Program or proceed to the appropriate section to continue setting up the temperature...

Page 47: ...eed to the appropriate section to continue setting up the temperature control 4 1 5 8 Restoring the Default Values To reset the Setpoint Proportional Band Integration Time and Max Duty Cycle parameter...

Page 48: ...until you exit the User Program Table 62 From Temp Control Use the and keys to select Default and press ENTER Int Time Max Duty Cycle Default POWER ESC ENTER Table 63 Tem Unit Measuring This message...

Page 49: ...ence the CGA 351 is preprogrammed at the factory with Auto Range default values that are suitable for many applications These values are listed in Table 64 below For example Range 3 is set for 0 10 pc...

Page 50: ...Range Table 65 Cfg Cal Opt Disp Use the and keys to select 1 Cal and press ENTER 1 Cal 2 Cal POWER ESC ENTER Table 66 Setup Cal Diag Use the and keys to select Setup and press ENTER Slct Cal Menu Item...

Page 51: ...Zero and Span Points The above step will be repeated as many times as necessary to complete the table for the total number of ranges selected on page 44 Table 69 A Auto_Range_Units Use the and keys to...

Page 52: ...e To set up the fault alarm enter the User Program as described on page 27 and proceed as follows Note The Lock All and Versions options are also available in the above list box Note The Backlight and...

Page 53: ...ws Note The Backlight and Comm options are also available in the above list box Table 74 User Fault Alarm Use the and keys to select the desired alarm type and press ENTER Non Fail Safe Fail Safe POWE...

Page 54: ...ange Span Setpoint enter the live measurement value that corresponds to the high end of the analog output range minus the zero setpoint Test specify a fixed percentage of the analog output range and v...

Page 55: ...requires a 4 20 mA output to be clamped in specific bands to indicate out of range errors Note The 0 2V option is software selected and therefore there is no need for hardware modifications to output...

Page 56: ...meter now automatically returns to the Analog Output prompt Either press ESC until you exit the User Program or proceed to the appropriate section to continue setting up the analog output Table 80 Us...

Page 57: ...he meter now automatically returns to the Analog Output prompt Either press ESC until you exit the User Program or proceed to the appropriate section to continue setting up the analog output Table 82...

Page 58: ...specified test values When done press ENTER IMPORTANT The edit box above must be exited by pressing ENTER while in edit mode and re entered for the analog output device to drive the previously entere...

Page 59: ...for the zero trim The meter now automatically returns to the Analog Output prompt Using the procedure under Testing the Analog Output on page 52 reset the Test Percent to its normal value Either pres...

Page 60: ...lue for the span trim The meter now automatically returns to the Analog Output prompt Using the procedure under Testing the Analog Output on page 52 reset the Test Percent to its normal value Either p...

Page 61: ...e programming the analyzer 4 1 11 Setting the Display Backlight To set the LCD display backlight enter the User Program as described on page 27 and proceed as follows Table 90 Cfg Cal Opt Disp Use the...

Page 62: ...r continue programming 4 1 12 Setting Up the Serial Port To set up the serial port enter the User Program as described on page 27 and proceed as follows Table 94 Cfg Cal Opt Disp Use the and keys to s...

Page 63: ...data bits in each data string Table 98 Cfg Cal Opt Disp Use the and keys to select Opt Then Use the and keys to select User and press ENTER User Setup Lock Menus POWER ESC ENTER Table 99 User Use the...

Page 64: ...e User Program or proceed to the appropriate section of this chapter to continue programming the meter IMPORTANT Check to make sure the communication parameters selected match the settings on the comp...

Page 65: ...roceed as follows Note The Lock All and Versions options also appear in the above list box At the following prompt an option card may be added or removed in an expansion slot or options may be added o...

Page 66: ...procedure to add or remove additional option cards CAUTION Be careful when using Erase Slot or Erase Main to make sure the information is no longer needed Table 109 Setup Load Slot Use the and keys t...

Page 67: ...menus Lock All this option institutes password protection for all submenus simultaneously Versions this option displays the software versions for each of the system components After responding to any...

Page 68: ...as containing only CO is not recommended since the analyzer will not respond correctly to dry calibration gases that do not contain H2 However CO may be used if moisture is added to the gas by passing...

Page 69: ...on page 16 At the standard operating temperature of 700 C an oxygen level of 5 ppm corresponds to a raw sensor output of 223 108 mV Note Air calibration at 20 9 O2 0 0 mV is performed during the fact...

Page 70: ...onfigured to read the oxygen concentration in ppm Note The oxygen sensor calibration is actually accomplished by adjusting its operating temperature until the required mV output is achieved 3 Adjust t...

Page 71: ...em POWER ESC ENTER Table 118 Setup Cal Diag Use the and keys to select Heater and press ENTER Heater POWER ESC ENTER Table 119 PPM Percent Use the and keys to select PPM and press ENTER PPM Percent PO...

Page 72: ...ilt in diagnostics routine is included in the User Program To access this submenu proceed as follows Table 122 PPM Percent Cal Gas When ready use the and keys to select Next and press ENTER Start the...

Page 73: ...m POWER ESC ENTER Table 127 Cfg Cal Opt Disp Use the and keys to select Cal and press ENTER Slct Cal Menu Item POWER ESC ENTER Table 128 Cfg Cal Opt Disp A list of the slots available for calibration...

Page 74: ...onal band integration time and maximum duty cycle The meter now automatically returns to the Diag prompt This completes the viewing of the heater settings Press ESC until you exit the User Program Tab...

Page 75: ...propriate section of this chapter for installation instructions WARNING To ensure safe operation of the CGA 351 it must be installed and operated as described in this manual In addition be sure to fol...

Page 76: ...tions in Chapter 2 Installation and the wiring diagram in Figure 6 on page 14 to make sure that all wires are attached to the correct pins If any connections are loose turn the screws clockwise with a...

Page 77: ...ss the TC terminals One of the conditions listed in Table 134 below should occur 3 Complete the action recommended in Table 134 above Note If a voltage reading other than those listed above is obtaine...

Page 78: ...0 8296 610 24 5322 770 31 2429 620 24 9566 780 31 6553 630 25 3805 790 32 0668 640 25 8039 800 32 4773 650 26 2267 850 34 5150 660 26 6489 900 36 5278 670 27 0705 950 38 5154 680 27 4914 1000 40 4775...

Page 79: ...rnace leads One of the conditions listed in Table 135 below should occur Note The sensor furnace impedance may also be checked in the User Program Proceed to the Diag Impedance prompt as described on...

Page 80: ...this chapter and to Figure 5 on page 87 for help in troubleshooting each of the above situations Note For information regarding component locations and or wiring connections in an optional enclosure...

Page 81: ...reading drops in Step 2 above tighten all fittings by 1 8 turn and close the sensor enclosure cover If the oxygen reading gradually returns to 20 93 try tightening the fittings an additional 1 8 turn...

Page 82: ...sensor being out of calibration To correct the condition complete the following steps 1 The sample gas may be contaminated with combustibles from grease or oil in the plumbing The oxygen sensor will...

Page 83: ...he sensor enclosure cover If the oxygen reading gradually increases repeat Step 1 If the problem persists proceed to the next section CAUTION Do not tighten fittings more than 1 8 turn at a time Check...

Page 84: ...sponses should occur 1 If the recovery time is still too long the sample gas path through the oxygen sensor may be plugged with particulates Use of a blowback system contact the factory for assistance...

Page 85: ...cated at the base of the sensor The upper clip is electrically isolated from the lower clip by a non conductive band on the sensor body Both clips simply snap around the body of the sensor The followi...

Page 86: ...ygen sensor body 3 Remove the four screws that secure the sensor manifold mounting plate to the bottom of the sensor enclosure Make sure that the sensor does not hit the sides of the sensor furnace an...

Page 87: ...losure make a note of the terminal pins for each lead and pull the leads through the conduit and into the sensor enclosure 5 Remove the screw that secures the integral thermocouple clamp to the bottom...

Page 88: ...of the sensor furnace and loosen the two 2 terminal screws closest to the outer edge of the sensor furnace IMPORTANT Do not completely remove the terminal screws from the ceramic power block 6 Carefu...

Page 89: ...ction describes the proper procedures for replacing these parts The user serviceable parts located in the electronics enclosure see Figure 6 on page 14 include the following main power fuse digital pa...

Page 90: ...result in serious personal injury 2 Remove the four sets of mounting hardware and remove the electronics enclosure from its mounting surface 3 Remove the eight screws on the rear of the enclosure and...

Page 91: ...ns and or wiring connections in an optional enclosure see Appendix C 1 Disconnect the main power to the CGA 351 WARNING Failure to cut the main power at the external disconnect device before proceedin...

Page 92: ...CGA 351 User s Manual 703 1350 1 Basic I O PCB 703 1361 01 1 Quad Alarm PCB 32K EPROM 703 1376 1 CGA351 Sensor PCB 703 1362 1 CGA351 Interconnect PCB Table 137 Spare Parts List CGA 351 Part Number Qty...

Page 93: ...et Fitting Inlet Fitting Mounting Screw 6 pl Inlet Fitting Mounting Plate Manifold Fitting Nut Oxygen Sensor Ceramic Block Mounting Holes Thermocouple Mounting Bracket Mounting Screw Sensor Upper Clip...

Page 94: ...CGA 351 User s Manual 88...

Page 95: ...ss than 3 of reading per year Operating Temperature Typical 700 C Maximum 950 C Pressure Effect Less than 0 2 of reading per mm Hg Sample Flow Rate Influence Per 40 cc min flow change at 400 cc min 0...

Page 96: ...quirements Relative Humidity 0 90 Temperature 25 to 50 C 13 to 122 F Power Requirements 110 115 or 220 240 VAC 50 60 Hz 250 W maximum Fuse 3 A 250 V 5 x 20 mm anti surge European Compliance This unit...

Page 97: ...al 91 Chapter 6 LTR CATEGORY OPTIONS B Voltage 1 100 VAC 2 115 VAC 3 220 VAC 4 240 VAC C Package 1 Standard Design on wall mount plate 2 Rack Mount D Inlet Outlet Tube Fitting 1 1 4 inch tube fitting...

Page 98: ...Chapter 6 92 CGA 351 User s Manual no content intended for this page...

Page 99: ...ntial gradient acting in the opposite direction thus tending to oppose further diffusion A 1 2 Equilibrium Conditions Under equilibrium conditions the potential gradient exactly balances the concentra...

Page 100: ...to the linearizer circuit The circuit produces a linear analog output that represents the percentage of oxygen in the sample gas and this signal is available for display on the digital panel meter an...

Page 101: ...3 7 229 421 7 2 215 463 0 3 282 090 3 8 228 862 7 3 215 174 0 4 276 059 3 9 228 317 7 4 214 889 0 5 271 381 4 0 227 786 7 5 214 608 0 6 267 559 4 1 227 269 7 6 214 330 0 7 264 327 4 2 226 763 7 7 214...

Page 102: ...93 5 4 221 495 8 9 211 020 2 0 242 318 5 5 221 110 9 0 210 785 2 1 241 295 5 6 220 732 9 1 210 554 2 2 240 320 5 7 220 361 9 2 210 325 2 3 239 388 5 8 219 997 9 3 210 098 2 4 238 496 5 9 219 638 9 4 2...

Page 103: ...ow Voltage Directive 73 23 EEC the analyzer requires an external power disconnect device such as a switch or circuit breaker The disconnect device must be marked as such clearly visible directly acces...

Page 104: ...Appendix B 98 CGA 351 User s Manual...

Page 105: ...nt enclosure types C 1 2 Rack Mount Installation The CGA 351 analyzer is available in a rack mount enclosure for installation in a standard 19 electronics rack see Figure 6 below Figure 6 CGA 351 Rack...

Page 106: ...y The only remaining connections to be made are at the rear panel terminal strip for those outputs being used see Figure 7 above and Figure 9 on page 102 Connecting The Outputs The terminal block on t...

Page 107: ...d Calibration for instructions on using the meter C 1 4 Rack Mount Service and Maintenance To access the components and wiring in the rack mount CGA 351 it may be necessary to remove the unit from its...

Page 108: ...pry it open 3 Using needle nose pliers pull each of the two fuse holders with an arrow printed on the end straight out of the unit 4 Replace the fuses with new ones of the same type and rating See Cha...

Page 109: ...s Manual 103 Dimensions are in inches millimeters 17 15 436 18 44 468 7 00 178 18 25 464 0 90 23 5 25 133 19 00 483 19 78 502 18 67 474 6 75 171 Figure 10 CGA 351 Rack Mount Version Outline and Mounti...

Page 110: ...Failsafe Mode TB1 OUTPUTS HEATER TC Thermocouple Furnace Any Gnd Shield 1 2 Furnace G G Any Gnd Shield Thermocouple O2 Group Description TB2 INPUTS Pin Sensor Sensor ALL ALL 6 White 5 White N A G Whit...

Page 111: ...Hot surfaces Zirconia Oxygen Analyzer Output Terminal Block Sample Meter Bypass Meter Digital Panel Meter Main Printed Circuit Board Gas Fittings Sensor Enclosure see Figure 5 2 Figure 12 CGA 351 Rac...

Page 112: ...CGA 351 User s Manual 106...

Page 113: ...ng 55 Components 16 Configuring 16 Contrast Adjusting 55 Multiple Windows 22 Output Devices 19 Parameters 18 Replacing 84 Testing 75 Disconnect Device 7 9 Display See Digital Display E EMC Compliance...

Page 114: ...ng 73 Wiring 11 Sensor Furnace See Furnace Serial Port Baud Rate 57 Data Bits 57 Node ID 57 Parity 58 Setting Up 56 Stop Bits 58 Type 58 Wiring 10 100 Software Versions 61 Spare Parts List 85 Specific...

Page 115: ...rds EN 61326 1998 Class A Annex A Continuous Unmonitored Operation EN 61010 1 1993 A2 1995 Overvoltage Category II Pollution Degree 2 following the provisions of the 89 336 EEC EMC Directive and the 7...

Page 116: ...nitored Operation EN 61010 1 1993 A2 1995 Overvoltage Category II Pollution Degree 2 suivant les r gles de la Directive de Compatibilit Electromagn tique 89 336 EEC et de la Directive Basse Tension 73...

Page 117: ...61326 1998 Class A Annex A Continuous Unmonitored Operation EN 61010 1 1993 A2 1995 Overvoltage Category II Pollution Degree 2 gem den Europ ischen Richtlinien Niederspannungsrichtlinie Nr 73 23 EG u...

Page 118: ......

Page 119: ...ct and company names are trademarks of their respective holders 910 199 Rev D Customer Support Centers U S A The Boston Center 1100 Technology Park Drive Billerica MA 01821 U S A Tel 800 833 9438 toll...

Search results

Summary of Contents for CGA 351

Reviews:

Panametrics CGA 351, User Manual, Page: 75 / 119

Search results

Summary of Contents for CGA 351

Reviews: