ABBE MARK III - Reichert Technologies: Analytical Instruments
Contents
1. Automatic Temperature Equilibration Temperature equilibration of a sample to that of the refractometer is essential for accurate measurements Automatic temperature equilibration will detect when the sample and prism have reached thermal stability This option can either be turned off or set between 0 01 C to 0 10 C A lower selected temperature value will increase the sensitivity and time for the sample to reach temperature stability Some experimentation is required to determine the best setting for a specific application To properly use this feature apply the sample and press the GD key After the Mark III displays that the temperature of the sample is stable align the shadowline and press amp D to attain the sample value 11 12 Menu Options Password RS232 Baud Date D The purpose of a Password is to limit user access and protect features from being altered by anyone other than an administrator Features that are deemed to be restrict ed may have their status changed to either Yes or No for Password protection by entering the Setup screen To enter a Password advance to the Change screen The first numeral will flash Follow the displayed instructions on how to change advance and exit The Password op tion can be turned On or Off under the Password menu options It is advisable that the password be recorded and secured in case it is forgot ten Once the Password is active it will not be p2. ABBE MARK III REFRACTOMETER USER GUIDE Analytical Instruments Introduction Congratulations on the purchase of your new Reichert Mark III transmitted light refractometer This manual describes the proper operation and care of this state of the art instrument The purpose of this instrument is to aid quality control personnel in food and beverage medical pharmaceutical industrial fluids chemical and petrochemical applications The Mark III s simple yet advanced features make it a well suited and widely used instrument The Mark Ill refractometer is a high precision optical instrument To obtain the best possible accuracy it is absolutely necessary to maintain the instrument The precision and accuracy of a refractive index measurement is largely dependent upon operator skill cleaning practices temperature control accuracy of calibration standards chemical stability and the physical char acteristics of the sample Use of good laboratory practice is essential Reichert recommends that daily calibration with distilled water be performed as a minimum requirement To assure the longest life of your Mark III always store the instrument with the prism surfaces and instrument clean and dry to prevent premature failure of the prisms and seals due to any harmful effects from sample residue The instrument is programmed to read out directly the refractive Index percent solids and the temperature of samples The percent solids scale is
3. Illumination Six high intensity LED s e Prism Assembly Stainless steel assembly with glass prisms e Range Channel 1 1 3000 1 7000 nD 0 95 Brix per ICUMSA e Readability 0 0001 nD 0 1 Brix e Precision 0 0001 nD 0 1 Brix e Channel Options Channel 1 Refractive index Brix Sucrose ICUMSA Channel 2 15 User defined Numerous scales available e Temperature Compensation Range 10 40 C e Sample Types Transparent and translucent liquids or solids e Sample Temperature Control Water bath circulator ports on upper and lower prism assemblies e Data Output Two 9 pin RS232 serial ports Instrument Features Focusing Eyepiece rotate to attain sharp focus of the X pattern and the shadowline Color Dispersion Correction Wheel rotate wheel to reduce color dis persion and attain a sharp clear shadowline Menu Key A Illumination and LCD Display Sample Prisms Up Down Keys Select Key Shadowline Adjustment Knob rotate to center shadowline R within X pattern 2 RS232 Serial EiChert Ports On Off Switch Calibration Oil Set Up Unpack the instrument from shipping carton Retain packing material for future storage protection shipping Place the instrument indoors on a solid surface in an environment where the temperature is stable Be certain that the instrument is not subjected to direct discharge from heating or air conditioning vents or water b
4. Reichert Instruments GmbH Hubertusstrasse 2 D 82229 Seefeld Germany Tel 49 8152 993530 Fax 49 8152 9935311 ISO 9001 Certified CE Reichert Analytical Instruments 2003 Reichert Inc Depew NY USA 13104880 101 Rev D
5. areas of the instrument simply wipe with a soft cloth and a mild soap and water solution A typical house hold glass cleaning product works well Cleaning Precautions The sealant used between the prism and stainless steel block may be attacked by certain chemicals Reichert recommends avoiding strong solvents such as N N Dimethylformamide or N N Dimethylacetamide Tetrahydrofuran cresols phenols and other tar acids Some lacquer thinners can also deteriorate the seal over time or when used at elevated temperatures To determine if your samples or solvents may attack this seal please contact Reichert Analytical technical support Scratched optical surfaces can have an adverse effect on shadowline clarity In the case of a sample having been allowed to dry on the prism surfaces never use abrasive materials to remove that sample Instead redissolve the sample with an appropriate solvent to protect the prism surface from being scratched Thick sticky samples should be rinsed off with a suitable solvent to avoid possibly scratching the prism Use caution when removing samples or drying the prism Accessories Catalog No Catalog No Catalog No Catalog No Catalog No Catalog No Catalog No Catalog No Catalog No Catalog No Catalog No Catalog No Catalog No 13981000 13982000 13107040 901 13981000 103 WFAG20047 13K41330 13K41340 13K41350 13K41360 13K41370 13K41380 13K41390 13104520 Printe
6. based upon the ICUMSA conversion tables relating refractive index to percent solids concentration for sucrose solutions For non sucrose solutions they may be read directly in the refractive index mode non temperature corrected or in the percent solids mode provided that the conversion value is known For product specific measurement custom channels also may be programmed into the Mark Ill Custom channels allow the instrument to read out directly in refractive index or percent solids temperature compensated values For more information regarding custom channel programming contact Reichert Analytical Instruments Technical Service Product Registration Please visit our web site at www reichert com to register your new Refractometer Click on Analytical Instruments Support Register your Reichert product In doing so Reichert Analytical Instruments will be able to provide you with technical support and information updates as they become available Reichert Analytical Instruments Preliminary Information Features and Requirements Sample Analysis Quick Start Operation Operational Parameters Maintenance Accessories Warranty Table of Contents Table of Contents Warnings and Cautions Symbol Information Environmental Conditions Electrical Ratings Specifications Instrument Features Set Up Sample Analysis Measuring Solid Samples Menu Options Overview Calibration Set Point Calibration Span Point Ca
7. The use of a custom channel allows comparing readings to a formula or process specification at a predetermined temperature without doing complicated conversions Please note that custom channels to do temperature correction are specific to the material that the channel was developed for and most likely will provide poor readings if used for a different material Computer Interface The Mark III includes two serial communications ports Fig 11 Both are DB9 position female connectors that are located on the left side of the instrument Data may be downloaded to a computer and custom channel files can be uploaded to the refractometer or deleted through these ports Regardless of which of the serial ports is chosen on the Mark Ill communi cations with a computer is possible Any Windows based computer can be used successfully when interfacing Fig 11 with the Mark III Communication through software such as HyperTerminal or Tera Term is required HyperTerminal is usually found on all Windows based systems as a standard software option Recommended communi cation settings of the serial port from the computer are Baud rate 9600 8 Data Bits No Parity 1 Stop Bit and Xon Xoff Flow Control Please note that the Baud rate of the instrument must match that of the computer To connect the instrument to a computer use a compatible serial cable Connection must be made while the instrument is turned off To set up an output text string refere
8. an point calibration The proper use of this option is covered in more detail under Span Point Calibration Edit Data This option allows the stored calibration values to be modified Follow the on screen instructions pertaining to changing values advancing and exiting this option Restore Factory Restores original factory default settings This option cannot be used as a substitute for an actual calibration procedure Channel The option to select a channel is only available if a custom channel has been stored To select any available channel advance to Channel and press All available channels will be displayed Advance to desired channel and press amp amp to activate The choice of four reading modes are available Additional reading modes may be available if a custom channel is active To change mode select the required mode option and press amp to activate Index Refractive index Index TC Refractive index temperature corrected Solids Percent concentration Brix Solids TC Percent concentration temperature corrected Brix O Q D An alternate method of changing modes exists in the reading screen once a sample has been measured All that is required is to press the 0r LP keys to advance through the available reading modes on the LCD screen Language English French Spanish and German are available language options To activate one of these options advance to the language of choice and press
9. ath circulator exhaust Drafts can have an adverse affect on temperature stability Insert the appropriate plug end into the power receptacle located on the underside of the instrument Plug the opposite end of the power cord into a receptacle to supply the instrument with power Fig 1 Supply voltage 100 240VAC 50 60HZ Turn the instrument on by activating the power switch located on the right side cover Fig 2 Allow the instrument to reach a stable operating temperature in the on position for a minimum of Fig1 one hour before attempting calibration or to measure samples Fig 2 Sample Analysis Cleanliness sample temperature equilibration and shadowline clarity is essential to obtain the greatest possible accuracy from the Mark Ill refractometer Highly viscous samples or samples that contain trapped air bubbles may not produce a sharp shadowline In these cases applying the sample with a rubber spatula to squeeze out trapped bubbles or lifting the upper prism sev eral times to remove the trapped air is required The following are the required steps to properly analyze a sample TR Raise the upper prism and apply the sample to a clean measuring surface Fig 3 Gently lower the upper prism to spread the sample evenly and to eliminate trapped air bubbles Fig 4 Allow the sample to reach temperature equilibration with the instrument View the image through the focusing eyepiece Fig 5 If required rotate the eyep
10. bration Points Calibration fluid values may change from one lot number to the next It is also possible to use alternate fluids to calibrate this instrument As a result it will become necessary to edit the stored values to match any new calibration standard To edit a value select Calibrate Advanced Options and press Under Advanced Options select Edit Data and press Follow the displayed instructions to select a stored value and press The value chosen should be the closest value to the new standard Use the and keys to edit the highlighted value and the amp D key to advance All three values must be updated to match the new standard or improper calibration will result Press to exit Before the altered value is stored a Save these values screen will appear Use the or EP keys to select either Yes or No and press to continue To return to the calibration menu options screen or the reading mode follow the displayed choices to exit Sample Temperature Effects on Readings Refractive Index is a physical property of a material Refractive index measurements and the percent solids results derived from them are very dependent upon temperature For most samples raising the temperature will lower the refractive index of a sample Conversely lower ing the sample temperature will raise the refractive index This change in refractive index due to a change in temperature will cause an appare
11. e type the command autoplus and press the return key on the computer key board If the computer link is successful and the baud rates match appropriately the return on the computer display will be Enter 99 to erase all channels X to erase channel X 0 to cancel or begin custom channel file upload Select File then Send File from the pull down menu located on the computer interface screen Browse through your directories to locate the desired custom channel file to select it and select open to load file To check that the file loaded correctly type Channeldata X X represents the location of where the channel has been stored from 2 through 15 If successfully loaded the channel data will be displayed as it appears in the text file To delete a stored custom channel follow the instructions above and type autoplus Re move files by typing 99 to remove all channels or X to remove a specific file and press the enter key on your computer key board Menu Options Calibrate The Calibrate option provides two calibration choices and two advanced feature options Once appropriate choices have been made advance to Exit and press amp to return to Menu Options screen Adjust Set Point Allows for a single set point calibration using distilled water This option is covered in more detail under Set Point Calibration Adjust Span Point Allows up to six additional calibration points to be used when performing a sp
12. e contact fluid that has a higher refractive index value than the sample being read Fig 9 Reichert recommends Bromonapthalene for any solid that will not be adversely affected by this liquid Place the polished side of the solid sample down on the contact fluid avoiding air bubbles from being trapped in the process Also place the polished perpendicular side toward the light source of the Mark III Fig 10 To complete the measurement process follow the procedure outlined in the section Sample Analysis Note Do not lower the upper illumination prism onto a solid sample as it may cause damage to the instrument Menu Options Overview Shown below are the menu options as they appear on the instruments display While many of these options are not required to operate the instrument they have been made available to enhance the functionality of the Mark III refractometer To access the menu options screen press the BD key To select an option press the or P keys to advance to and highlight the desired option Press the key to enter and view the sub menu options Using the and EP keys scroll through the option choices and press ED when the desired selection is highlighted Calibration To properly maintain the accuracy of the Mark III refractometer calibration of the instrument on a routine basis is recommended Prior to calibration it is extremely important to completely clean the prism surfaces so no sam
13. e desired temperature of the Mark III The exact temperature setting is dependent upon circulating fluid type flow rate ambient temperature humidity etc Experimentation may be necessary to determine an appropriate water bath temperature setting to maintain a stable temperature at the Mark III The instrument temperature as indicated in the lower left corner of the display should be what dictates the water bath temperature setting When attempting to determine the appropriate water bath temperature setting It may be helpful to have a distilled water sample on the prism to improve thermal conductivity between the upper and lower prism assemblies 13 14 Care and Cleaning a gt 4 Preparing the prism surfaces for samples is essential if consistent and accurate values are to be attained Prior to and immediately after a sample is placed on the prism surface those surfaces must be properly cleaned Fig 14 It is imperative that these surfaces be cleaned to assure removal of any possible residue since this condition will have an adverse affect on resultant readings Never allow a sample to dry on the prism surfaces Fig 14 Depending upon the sample clean the lower measuring prism and the upper illumination prism using distilled water diluted soapy water isopropyl alcohol or methanol Rinse with distilled water and gently dry using a lint free product like Kim Wipes that will leave no residue To properly clean the body or display
14. iece to bring the image of the X pattern into focus If a non distinct shadowline containing color is viewed rotate the color dispersion correction wheel to eliminate or reduce the color dispersion Fig 6 Under optimal conditions the shadowline area will appear to be sharp and black with a bright area above Fig 6 While viewing the image center the shadowline in the X pattern by rotating the shadowline adjustment knob Fig 7 For measuring consistency always approach the center of the X pattern with the shadowline from below Once the image has been centered Fig 8 press Fig 8 To the left is a representation of a displayed value To change reading mode press either PD or EP to advance through all available mode options Measuring Solid Samples The Mark Ill is capable of measuring transparent or translucent plastic or glass solid samples with the upper prism raised The instrument can also be used to measure very thin pliable solids such as contact lens material that can fit between the prisms when closed Solid samples must be shaped and polished correctly in order to be read The size of solid samples should be no larger than 35mm Long x 12mm Wide x and a minimum of 2mm High Also one side of the sample and one of the perpendicular surfaces that will face the illumination source must be polished All other sides should be frosted for best results To measure a solid sample apply a drop of a suitabl
15. ities are generally available from laboratory instrument supply dealers Maximum head for water bath attachment should be 5 feet and maximum pressure 15 psi The minimum operating temperature of Mark Ill is 10 C and maximum is 80 C Using tubing having an inside diameter of 25 inches 6 4mm connect the output hose from the water bath circulator to either of the water ports on the lower measuring prism assembly Attach a second piece of tubing to the opposite water port and connect it to either of the upper illuminating prism water ports Ensure that this tubing is long enough to allow the upper illuminating prism assembly to open and close freely Next attach the return hose for the water bath circulator to the remaining water bath port Fig 13 Fig 13 Tubing choice must consider flexibility Any tubing that is highly rigid may apply excessive force on the prism preventing it from closing completely This condition can adversely affect reading accuracy Note If a water bath circulator is attached care must be used to avoid exposing the Mark III s prisms to thermal shock The ambient prism temperature should be raised or lowered by gradually increasing or decreasing the temperature of the circulating fluid Due to the nature of refractometer thermal efficiency Controlling the temperature of the instrument to a temperature above or below ambient may require the water bath circulator temperature to be set higher or lower than th
16. libration Editing Calibration Points Sample Temperature Effects on Readings Automatic Temperature Correction TC Computer Interface Printer Interface Custom Channel Activation Uploading Custom Channels Menu Options Water Bath Attachment Care and Cleaning Cleaning Precautions Printers Fuse Calibration Oil Bromonapthalene Warranty and Non Warranty Service O1 01 AUGU CO N NNOO 19 19 15 hs Warnings and Cautions Caution In order to insure that correct operation of the Mark Ill instrument is maintained any repair or service must be performed by experienced personnel that are trained by Reichert Inc Caution ESDS The internal circuitry of the Mark Ill contains electrostatic discharge sensi tive devices ESDS Such components may be sensitive to high voltages produced by static discharge Caution Do not use strong solvents or strong cleaning solutions on any part of the Mark Ill or damage to the unit may occur Warning Do not remove or defeat the earth ground connection on the Mark III power input connector or the unit s power cord Damage to the Mark III instrument and or injury to the op erator may occur Warning The Mark III should be used in strict accordance with the instructions outlined in this users guide The safety of the operator and the performance of the instrument cannot be guar anteed if used in a manner not specified by Reichert Inc Symbol Information The following symbol
17. nce Printer Output Printer Interface The printer output is provided for connecting an external printer through either of the two RS232 serial ports Both are DB9 position female connectors In order to communicate properly with a printer a Null Modem cable must be used and should be connected while the instrument is turned off Proper Baud rate selection of the RS232 serial port is also required and should be set at 9600 In order to set the output text string for the printer computer interface is required The options that exist for the output are as follows and can be arranged according to individual require ments a Temperature b Index c Index TC d Solids e Solids TC f Current Mode g Channel h Time Date j ID k Method Once communications with a computer is successful type sf and press the enter key on the computer key board This will display any current text output string To edit the string type sf then a space and enter the desired letter codes Example sf cagh With the example entry of cagh the instrument will print Index TC Temperature Channel and Time 10 Custom Channel Activation The Mark Ill has the capabilities to measure additional products using custom channels These channels represent scales that have been developed to measure a specific product Optional channels can be selected only after they have been uploaded from a PC to the Mark III The following desc
18. nt change in concentration unless the reading is temperature corrected TC Before a sample measurement can be temperature corrected however the sample needs to reach thermal equilibrium with the instrument Without tempera ture equilibration the resulting value cannot be considered accurate for direct read values or temperature corrected TC values This is the result of the sample being in a state of thermal transition while the refractive index value is captured by the instrument This is common with all refractometers Automatic Temperature Correction TC Automatic Temperature Correction TC is based upon three factors refractive index tempera ture and temperature coefficient The relationship of these three factors are used to math ematically correct a value as though it was read at a specific temperature The most common temperature corrected TC temperature is 20 degrees C but it can differ with individual require ments The temperature corrected reading modes TC in the Mark Ill are based upon sucrose temperature correction factors developed by ICUMSA Non sucrose solutions will have unique temperature correction factor Since most uses of a refractometer is to control concentration it is useful to eliminate the temperature effects when viewing instrument readings One standard method is to have pro grammed custom channels that calculate the correct reading at 20 degrees C for a sample that is being read at other temperatures
19. ossible to enter the protected Menu Options without it It is essential that the Baud rate be set properly for computer or printer com munications This option allows independent values to be set for each serial port Please note that the REAR serial port must be set greater than or equal to the FRONT serial port Please refer to the displayed instructions on how to change the Baud rate settings using the ED ED sys The time may be set in either AM PM or 24 00 00 format Use the or gt keys to change the displayed value To advance to the next time seqment use the GD key and the key to exit The Date format is DD MMM YY Use the EB P keys to change the displayed value To advance to the next Date segment use the GD key and the EQ key to exit To adjust the display contrast use the B EP keys To exit press the SD key The ID option is provided to enable tracking of individual users when the output is being sent to a computer or printer Follow the displayed prompts to enter a user ID or contact Reichert technical support for greater details concerning this option Water Bath Attachment Certain testing applications may require the prism temperature to be maintained above or below ambient operating temperature To accomplish temperature control the Mark III is supplied with four water ports for connection to a water bath circulator Fig 12 Commercial water bath circulators with heating cooling or combined capabil
20. ple residue is present Any residue on the prism surfaces will adversely affect the accuracy of the calibration Calibration options are either Set Point or Span Point Set Point calibration is performed using distilled water as the calibration standard Reichert recommends performing the Set Point calibration daily Span Point calibration is performed with distilled water and up to 6 additional calibration standards It is not essential to calibrate at every available point Span Point calibration with distilled water and at least one calibration standard is recommended to ensure accuracy across the reading range of the instrument Span Point calibration standards can be chosen to closely match the reading range of the product being analyzed Set Point Calibration Advance to the Calibration Adjust Set Point menu op tion and press Apply distilled water as the calibration standard as de scribed under Sample Analysis and allow to equilibrate to the instrument temperature Adjust shadowline to the center of the X pattern and press amp D to calibrate or to cancel Upon completion the display will revert to the Calibrate menu option screen Press SP to return to the reading mode Span Point Calibration The Span Point calibration option allows for up to six additional calibration points These points can be chosen to either calibrate across the entire reading range of the instrument or to closely match a specific range
21. r 110 VAC Printer 220 VAC Null Modem Cable Paper 5 Rolls FUSE 800mA 250V 5X20MM NIST Certified Calibration Oil 1 514XX NIST Certified Calibration Oil 1 402XX NIST Certified Calibration Oil 1 457XX NIST Certified Calibration Oil 1 489XX NIST Certified Calibration Oil 1 572XX NIST Certified Calibration Oil 1 630XX NIST Certified Calibration Oil 1 360XX Above values will vary due to supplier of oil and lot numbers editing the stored values in the refractometer may be required Bromonapthalene Used as contact fluid when measuring solid samples Warranty and Non Warranty Service The warranty period for this instrument is two years against manufacturing defects Please visit our web site at www reichertai com and select Terms and Conditions of Sale for an explanation of the warranty The Mark III refractometer is a precision instrument Only Reichert factory trained service techni cians should perform repairs to assure proper functionality and sustained precision If service is required please contact our Reichert Service Department at Reichert Analytical Division headquarters in Buffalo New York USA 716 686 4500 Country Code 001 or our service facility located in Seefeld Germany at 49 8152 993530 15 Reichert Analytical Instruments Reichert Inc 3362 Walden Ave Depew NY 14043 USA Toll Free 888 849 8955 Phone 716 686 4500 Fax 716 686 4555 email ai reichert com www reichert com
22. ribes the Mark Ill custom channel possibilities Channel 1 ICUMSA BRIX The Mark III is pre programmed at the factory with channel 1 to read Sucrose or Brix scale per the International Commission for Uniform Methods of Sugar Analysis ICUMSA Tempera ture Corrected TC readings in channel 1 are valid for Sucrose only This channel cannot be altered Channel 2 15 User Programmable User programmable or custom channels as they are commonly referred to may be programmed using your own Refractive index Temperature and per cent Solids data Custom channels can include definitions for units of mea sure such as specific gravity protein g ml etc To access and activate a stored custom channel advance to the Menu Options Channel screen Select from the displayed channel options and press the GED key to activate the highlighted custom channel For a complete list of custom channels available from Reichert please visit our web site at www reichertai com Click on Applications and open the document titled Custom Scales Avail able To learn more about custom channel programming request Custom Channel Generation for Automatic Refractometer Line from Reichert Analytical technical support Uploading Custom Channels To upload a custom channel begin by connecting the Mark III to a computer as described un der Computer Interface and follow the steps below Once the connection to the computer has been mad
23. s appear on the instrument CAUTION Risk of Electrical Shock CAUTION Indicates that important operating and maintenance instructions are included in this user guide CAUTION Replace with the same type and rating fuse Date of Manufacture Waste of Electrical and Electronic Equipment Serial Number Catalog Number Ground On Off Conformity with mandatory European safety requirements Environmental Conditions e Indoor use only e Operating temperature range 10 C 80 C e Maximum relative humidity 80 for temperature up to 31 C decreasing linearly to 50 relative humidity at 40 C e Installation category II over voltage category e Pollution degree 2 e Altitude up to 2 000 meters Electrical Ratings Specifications The Reichert Mark Ill refractometer incorporates an auto sensing switching AC power supply Never use an adapter between the power cord and the power source which will interrupt the protective grounding e Caution Risk of electrical shock exists if any cover of the Mark Ill is removed Hazardous voltages will be exposed which can cause injury or death Refer servicing to a Reichert trained service technician e Supply Voltage 100 240VAC 50 60HZ e Fuse Rating 800mA 250V 5x20mm e Power Cords US EU UK supplied e Dimensions 11 L x 6 25 W x 13 75 H 280 mm x 258 mm x 345 mm e Net Weight 17 25 pounds 7 84 kg e Display LCD 1 85 W x 1 85 H 47 mm x 47 mm e
24. where samples are typically read The instrument does not have to be calibrated at every available point If you have specific requirements Reichert offers NIST certi fied calibration fluids as an accessory to this instrument One bottle of NIST certified calibration oil catalog number 13K41330 is included with the instrument Note Prior to performing the Span Point Calibration process Set Point Calibration must be completed Advance to the Calibration Adjust Span Point menu option and press Follow the displayed instruction to either activate or inactivate a calibration point Points preceded by are active and those preceded by are inactive The choice of these points are dictated by which calibration standards are available at the time of calibration Proceed with the calibration process by advancing to Continue on the display screen and pressing amp amp As the active calibration values are displayed add that calibration fluid and allow to temperature equilibrate Position the shadowline on the center of the X pattern and press GD to calibrate or GED to cancel Promptly clean the calibration fluid from the instrument to remove all residue The above step will be repeated until all active points are calibrated After the last active point has been calibrated the display will return to the Calibrate option screen Advance to Exit and press Press GDP to return to the reading mode Editing Cali
Download Pdf Manuals
Related Search