Artel PCS 2 Скачать руководство пользователя страница 18

Страница: 18 / 68

15A3356O

Enter the Operator ID (not exceeding 20 digits or characters) for
this calibration and press

ENTER

. This ID appears on the Printout.

For alphabetic character entry, see Appendix E. If the ID is entered
incorrectly, press

CLEAR

and enter the correct ID.

4.5

Entering Pipette ID Number

At the prompt:

Enter Pipette ID:

Enter the Pipette ID (not exceeding 20 digits or characters) for this
calibration and press

ENTER

. This ID will be printed on the PCS Printout

for pipette cross-referencing, and as a hard copy record. For alphabetic
character entry, see Appendix E.

The Instrument will print the information just entered and display:

*** Printing ***

Please Wait

Followed by:

Enter Pipette

Volume: _ uL

4.6

Entering Pipette Volume

Enter the volume (in microliters) to be dispensed, and press

ENTER

. The

CLEAR

key can be used to correct an entry error prior to pressing the

ENTER

key.

NOTE:

This volume must be entered in microliters ranging from 0.1 μL through 5000 μL.

The number of samples that can be added at this pipette volume in
this vial will be displayed:

XX Left this Vial

Proceed? (Yes/No)

Press

YES

. The following prompt will be displayed:

Range X

Please Wait

The Instrument will take a final Blank reading, and then prompt:

Содержание PCS 2

Страница 1: ...6O PCS 3 Procedure Guide 25 Bradley Drive Westbrook Maine USA 04092 2013 tel 207 854 0860 toll free 1 888 406 3463 fax 207 854 0867 email orders artel usa com email support artel usa com web www artel usa com ...

Страница 2: ... Artel PCS and its components are covered by patents listed at www artel usa com patents All Artel product Safety Data Sheets are available at www artel usa com support ordering All rights reserved No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without the prior written ...

Страница 3: ...ce 10 4 3 Starting Pipette Calibration 10 4 4 Inserting the Blank Vial 13 4 5 Entering Pipette ID Number 14 4 6 Entering Pipette Volume 14 4 7 Pipetting Sample Solution 15 4 8 Pipetting Additional Samples 17 4 9 Eliminating Sample Readings and Reprinting Results 17 4 10 Performing Additional Calibrations In One Vial 18 4 11 Continuing a Calibration Run with Another Vial 20 4 12 Calibrating an Adju...

Страница 4: ...ty 35 6 10 Signature Block 36 7 0 TROUBLESHOOTING 7 1 Instrument Diagnostics Menu 37 7 2 Troubleshooting Guide 40 8 0 SYSTEM MAINTENANCE 8 1 Preventive Maintenance 45 8 2 Instrument Calibration 45 8 3 Removal of Rear Access Cover 45 8 4 Maintenance Log Sheet 46 9 0 WARRANTY AND SERVICE 9 1 Warranty Statement 47 9 2 Return and Repair 47 APPENDICES Specifications A PCS Printouts B Formulas Used to C...

Страница 5: ...its SI through reference standards developed and maintained by the National Institute of Standards and Technology USA NIST The volume of liquid delivered is immediately calculated and displayed for each data point A Printout is generated displaying the volume of each sample and the group statistics The Printout includes such information as pipette ID operator ID time temperature and date to assist...

Страница 6: ...15A3356O 2 This Page Intentionally Left Blank ...

Страница 7: ...3 2 0 INSTRUMENT PREPARATION 2 1 Location The Instrument should be located in an area that is out of direct sunlight and away from local heat sources e g an oven or heat vent 2 2 Set up and Cabling Illustration ...

Страница 8: ...ll above connections are firmly in place 2 3 2 Connecting the Seiko Printer to Power NOTE If the STAR Dot Matrix Printer is being used please refer to the STAR Printer User s Manual for printer connection and operation Plug the Printer AC adapter into an appropriate receptacle Plug the remaining end of the adapter into the power receptacle located at the rear of the Printer 2 3 3 Connecting the Pr...

Страница 9: ...per roll cleanly and squarely Insert the end of the paper into the inlet at the bottom of the paper holder until the auto loader catches it and feeds it through The outside of the roll is the printable surface for the thermal paper roll Close the paper cover NOTE A red line will appear on both sides of the paper when the paper roll nears depletion This indicates that the paper roll should be chang...

Страница 10: ...15A3356O 6 This Page Intentionally Left Blank ...

Страница 11: ...te volumes 2 to 9 μL NOTE Range 5 for pipette volumes 0 5 to 1 9 μL and Range 6 for pipette volumes 0 1 to 0 49 μL are sold separately Sample Aliquot Containers 12 Used to contain an aliquot of Sample Solution Transfer Pipettes 12 Used to transfer an aliquot of Sample Solution into a Sample Aliquot Container Calibration Standard 1 CAL A used for zeroing the Instrument daily Kit Inserts 1 Declarati...

Страница 12: ...tion of the vial about 2 5 cm into clean isopropyl alcohol 3 2 2 Remove the vial from the alcohol and while wearing gloves gently wipe the lower portion of the vial by rotating the vial against a lint free wipe 3 3 Storage The Reagent Kit should be stored at room temperature 18 C to 28 C Avoid storage temperatures exceeding 32 C Kit components should be stored in the dark to the extent practical N...

Страница 13: ...volume MENU SCROLL Used to view the next question or a different question NO Used as a negative response to a question Enters a decimal point or period END OF RUN Terminates a pipette calibration run Group statistics for data collected up to that point of the procedure will be printed CLEAR Clears the data entry window or corrects the most recent invalid entry RESET Halts the procedure and returns...

Страница 14: ... be loaded into the Vial Block Inspect vials for smudges If cleaning is necessary refer to Section 3 2 Cleaning of PCS Vials 4 2 3 Upon power on the Instrument will perform a system test The following prompt will be displayed Main Menu Pipette Calibration NOTE To check the date and time and to edit the header information on the Printout refer to Section 6 0 Instrument Setup 4 3 Starting Pipette Ca...

Страница 15: ...ered Lot Codes If this Lot Code matches one previously entered proceed to Section 4 3 3 If the Lot Code does not match the display will prompt Rgt Lot Code XXXXX New Lot Y N If the Lot Code was entered incorrectly press NO and enter the correct Lot Code Press YES if entering a new Lot Code The Group Numbers found on the correct side of the Lot Code Card for the instrument type will need to be ente...

Страница 16: ...the vial facing forward Remove the CAL A Calibration Standard from the Vial Block 4 3 4 Open the Vial Holder Cover and insert CAL A into the Vial Holder pressing it down until it meets the bottom of the Vial Holder Never remove the cap of the CAL A Calibration Standard The following prompt will be displayed Please Close the Cover 4 3 5 Close the Cover The Instrument will then perform a Zero Check ...

Страница 17: ... the Instrument it must not be turned moved or removed until the calibration procedure is completed for all pipettes to be calibrated using that vial 4 4 1 Remove a Blank Reagent Vial from the Vial Block The Blank Reagent is light blue in color 4 4 2 Remove the cap open the Vial Holder Cover and insert the Blank Reagent Vial into the Vial Holder pressing it down until it contacts the bottom of the...

Страница 18: ...d copy record For alphabetic character entry see Appendix E The Instrument will print the information just entered and display Printing Please Wait Followed by Enter Pipette Volume _ uL 4 6 Entering Pipette Volume Enter the volume in microliters to be dispensed and press ENTER The CLEAR key can be used to correct an entry error prior to pressing the ENTER key NOTE This volume must be entered in mi...

Страница 19: ...ed Each kit contains bottles of Sample Solution corresponding to four different pipette volume ranges Refer to Section 3 1 Contents of Standard Reagent Kit If the improper Sample Solution has been pipetted into a Blank Reagent Vial the results obtained will not be valid and that vial is no longer usable and should be discarded 4 7 2 Using a disposable Transfer Pipette transfer an aliquot of Sample...

Страница 20: ...es provides the opportunity to improve technique and to optimize pipetting accuracy and precision For additional technique instructions contact ARTEL Technical Support and refer to the information included in the back of the Procedure Guide 4 7 3 Aspirate the Sample Solution from the Sample Aliquot Container with the pipette to be calibrated using standard pipetting technique Place the cap lightly...

Страница 21: ...librating an adjustable volume pipette at multiple volumes press ENTER and see Section 4 12 Calibrating an Adjustable Volume Pipette at Multiple Volumes The group statistics will be computed and the results printed 4 9 Eliminating Sample Readings and Reprinting Results NOTE Conformance with regulatory or other requirements relating to the provision of sufficient justification for the elimination o...

Страница 22: ...at can be collected with each Blank Vial will depend on the volume of Sample Solution added and range from 1 to a maximum of 40 Refer to Appendix F Each time a pipette calibration run is completed the Instrument will display the remaining number of samples of the selected volume that can be dispensed into the vial Additional calibration runs may be completed within the vial s allowed capacity The ...

Страница 23: ...Printout For alphabetic character entry see Appendix E If the ID is entered incorrectly press CLEAR and enter the correct ID The next prompt will instruct to enter the Pipette ID Enter Pipette ID _ Continue the calibration of the second pipette from Section 4 5 Entering Pipette ID Number When the vial s maximum capacity is reached the following prompt will be displayed Result XX XXX X along with t...

Страница 24: ...is pressed the Instrument will not retain the pipette ID number The group statistics for the first volume will be computed and the results printed At the next prompt Reprint Results Yes No If sample readings need to be eliminated from the statistical summary refer to Section 4 9 Eliminating Sample Readings for instructions If no sample readings need to be eliminated press NO At the next prompt Ent...

Страница 25: ... µL The absolute error for the nominal volume applies to every selectable pipette volume e g a 100 µL nominal volume yields limits of 2 0 µL inaccuracy mean value and 1 0 imprecision STD for all volumes The relative error varies throughout the pipette range e g for a 10 to 100 µL pipette at 100 µL the relative inaccuracy is 2 0 However at 10 µL the relative inaccuracy is 20 0 Notes a Inaccuracy is...

Страница 26: ...1 0 2 0 5 0 10 0 0 20 0 10 20 20 10 5 2 2 0 4 0 8 0 20 0 1 0 2 0 4 0 10 0 0 4 0 2 50 50 25 10 5 2 0 4 0 10 0 20 0 1 0 2 0 5 0 10 0 1 0 0 5 100 100 50 25 10 2 0 4 0 8 0 20 0 1 0 2 0 4 0 10 0 2 0 1 0 200 200 100 50 20 2 0 4 0 8 0 20 0 1 0 2 0 4 0 10 0 4 0 2 0 500 500 250 50 2 0 4 0 20 0 1 0 2 0 10 0 10 0 5 0 1000 1000 500 250 100 2 0 4 0 8 0 20 0 1 0 2 0 4 0 10 0 20 0 10 0 2000 2000 1000 500 200 2 0...

Страница 27: ...e the scope of impact analysis for out of tolerance findings The Instrument calibration is checked using the Instrument Calibrator Kit The Kit contains four vials CAL A B C and D with calibrator values lot code and expiration date which are located on the label on the inside of the box lid The calibrator values communicate reference information about the concentrations derived from a factory refer...

Страница 28: ...mpt will be displayed Temp out of range Continue Y N If NO is pressed the following prompt will be displayed Main Menu Pipette Calibration If YES is pressed to continue with the calibration there is no certainty that the results the PCS obtains will meet the system specifications 5 2 2 At the following prompt Enter Operator ID 1 Enter the Operator ID not exceeding 20 digits or characters for this ...

Страница 29: ...eagents is being used press YES The new calibrator values which are found on the insert card will need to be entered The calibrator values consist of three five digit numbers and need to be entered only when a new Calibrator Kit is used The leading zero if there is one and the decimal point must be entered Each group is entered separately Press ENTER after each group of digits At the next prompt e...

Страница 30: ...the last Instrument Calibration will change to the current day This date is printed on the footer of subsequent pipette calibration Printouts If the Instrument fails its calibration the date will not change See Appendix B for an example Printout NOTE Refer to Section 7 2 Troubleshooting Guide if the Instrument Calibration fails At the completion of the Instrument Calibration the results will be pr...

Страница 31: ...each wavelength for each of the CAL vials A Fail rating occurs if the standard deviation exceeds the specification Overall Calibration Result The overall calibration result is a Pass if each of the previous results was a Pass it is a Fail if one or more of the previous results was a Fail 5 3 Instrument Calibration Summary A printed summary report of the most recent instrument calibration can be ob...

Страница 32: ...ain Menu Instr Calibration Press YES Instrument Cal Menu Perform Instr Cal Press NO Instrument Cal Menu Print Cal Summary Press YES The calibration summary will be printed out See Appendix B for an example Printout ...

Страница 33: ...ction 6 2 Check Set Time See Section 6 3 Choose Date Format See Section 6 4 Edit Report Hdr 1 See Section 6 5 Edit Report Hdr 2 See Section 6 5 Computer Link Flags See Section 6 6 Data Collect Flag See Section 6 7 Choose Nomenclature See Section 6 8 Display Uncertainty See Section 6 9 Signature Block See Section 6 10 Go to Main Menu Use the MENU SCROLL key to reach the desired option Then press YE...

Страница 34: ... YES If the date is incorrect press NO and enter correct date 6 3 Setting Time Access this option using the Setup Menu Refer to Section 6 1 Instrument Setup Menu Press YES at the prompt Setup Menu Check Set Time The following prompt will be displayed Correct Time Y N XX XX If the time displayed is correct press YES If the time is incorrect press NO and enter the correct time NOTE The time is displ...

Страница 35: ...nt Setup Menu Press YES at the prompt Setup Menu Choose Date Format The following prompt will be displayed Date Format X Change Yes No Press YES The following prompt will be displayed Enter New Date Format _ Enter the number 1 2 3 or 4 for the date format desired and press ENTER 6 5 Customizing the Printout Header The two line header that appears at the top of the Printout can be customized to inc...

Страница 36: ...er of choice may be replaced by entering the appropriate code number and pressing ENTER Continue in this manner until all characters have been entered for the first line Once the first header line is completed edit the second line in the same way as the first If the RESET key is pressed in the middle of an editing session the original version of the header is saved and the instrument will return t...

Страница 37: ...back to the host PC as part of the calibration record Press YES to change the state of the Request Missing IDs flag If no change is needed press NO 6 7 Serial Data Output Data Collect Flag There are two ways the PCS can transmit calibration data to a PC over a serial link The more powerful uses the Link to Computer option at the main menu This option effectively gives control of the PCS to the hos...

Страница 38: ...n to the Setup Menu IMPORTANT The Data Collection setting should be turned on only if calibration results are being sent to a PC via the RS232 port Contact ARTEL for more information about this feature 6 8 Choose Nomenclature The summary statistics shown near the end of a PCS pipette calibration can be labeled with one of two different but equivalent nomenclatures The statistics and their labeling...

Страница 39: ...he print out if desired The calculation is made using data from the calibration including mean volume CV number of data points and standard uncertainties ui for each PCS Range Solution See Appendix C for calculation method Access this option using the Setup Menu Refer to Section 6 1 Instrument Setup Menu Press YES at the prompt Setup Menu Display Uncertainty To skip this setup option press NO If Y...

Страница 40: ...ection 6 1 Instrument Setup Menu Press YES at the prompt Setup Menu Signature Block To skip this setup option press NO If YES is pressed the following prompt will be displayed Sig block Omit Change Yes No or Sig block Include Change Yes No These prompts indicate whether the signature block is currently omitted from or included in the printout Press NO to keep the Signature Block setting as display...

Страница 41: ...ut turning the instrument over the instrument serial number is on a label on the bottom of the instrument or searching for a Printout it is near the bottom of most Printouts Software Ver No This entry is also for convenience to determine the software version number without removing the back cover the software version number is on a label on the program memory card or searching for a Printout it is...

Страница 42: ... determines if the filter wheel is able to select the filters properly It will allow a selection of one of two filters 520 nm or 730 nm If the filter wheel cannot be positioned to the selected filter an error message will be displayed Read Temperature This entry displays the PCS temperature as determined by the probe in the vial block NOTE Should the probe be disconnected as might happen if the re...

Страница 43: ...15A3356O 39 MENU SCROLL until the following prompt appears Diagnostics Menu Go to Main Menu 7 1 4 Press YES The instrument will return to the following prompt Main Menu Pipette Calibration ...

Страница 44: ...ly equilibrated to room temperature The kit should be allowed to adequately equilibrate to room temperature and the vials then placed in the vial block at least 15 minutes prior to use Vials not inserted in the vial holder in the proper orientation The vertical line on the labels for these vials should face toward the front of the instrument Bubbles in the vial due to excessive shaking prior to in...

Страница 45: ... SOFTWARE ERROR alternating with ERROR 14 Press Reset A PROM card containing an incompatible version of firmware was installed in the instrument Remove the PROM card and replace with one containing suitable firmware ERROR 16 FILTER WHEEL ERROR alternating with ERROR 16 Press Reset The instrument is unable to reliably position the filter wheel Call Artel Technical Support for assistance ERROR 24 TO...

Страница 46: ...pettes from 0 1 µL through 5000 µL Re enter the pipette volume making sure it is within the PCS range Invalid volume Re enter Yes No Volume entered is outside the range that the PCS is capable of calibrating The PCS can calibrate pipettes from 0 1 µL through 5000 µL Re enter the pipette volume making sure it is within the PCS range Invalid Re enter User is attempting to delete an invalid data poin...

Страница 47: ...error message persists turn instrument power switch off for 1 minute or longer then power back on If the problem still persists call Artel Technical Support for assistance Waiting for Data Collection Prompt The Data Collection output is turned on and the Instrument is waiting for a signal from a PC to send calibration results via the RS232 port If calibration results do not need to be sent to a PC...

Страница 48: ...15A3356O 44 This Page Intentionally Left Blank ...

Страница 49: ...mits access to the user replaceable PROM card CAUTION Disconnect all external cabling Prior to removal of cover components the power must be turned off and the external Power Supply unplugged from the Instrument 8 3 1 Locate and unfasten the two 2 quarter turn fasteners on the Rear Access Cover To unfasten the quarter turn fasteners use a screwdriver insert the blade in the slot and rotate 1 4 tur...

Страница 50: ...15A3356O 46 8 4 Maintenance Log Sheet PCS S N__________________________ Date Maintenance Performed Next Scheduled Maintenance Signature ...

Страница 51: ... non warranty repair or recertification contact the Artel Technical Support Department A Return Materials Authorization RMA number will be issued for all returns Telephone Local 207 854 0860 Toll Free 888 406 3463 Ship to Artel 25 Bradley Drive Westbrook ME 04092 2013 9 2 2 To ensure protection of the Instrument during shipment the original packaging should be used If the original packaging is not...

Страница 52: ...15A3356O 48 This Page Intentionally Left Blank ...

Страница 53: ... Less than 0 5 CV Operating Temperature 18 C to 28 C Printed Output Calibration data record 11 2 cm width with standard printer supplied PCS REAGENTS AND STANDARDS Blank Solution Vials Absorbance Maximum near 730 nm Shelf Life and Storage Minimum of 9 months at 18 C to 28 C closed box out of direct sunlight Sample Solutions Ranges 1 through 6 Absorbance Maximum near 520 nm Shelf Life and Storage M...

Страница 54: ...15A3356O This Page Intentionally Left Blank ...

Страница 55: ...tio Ratio Error Result B 1 0121 1 0122 0 00 Pass C 1 0049 1 0050 0 01 Pass D 0 9994 0 9985 0 09 Pass Spec all 3 cases 0 75 INSTRUMENT REPEATABILITY 520 nm Cal Std Dev Spec Result A 0 00005 0 00018 Pass B 0 00006 0 00016 Pass C 0 00008 0 00023 Pass D 0 00004 0 00050 Pass 730 nm Cal Std Dev Spec Result A 0 00002 0 00050 Pass B 0 00002 0 00050 Pass C 0 00004 0 00050 Pass D 0 00006 0 00050 Pass OVERAL...

Страница 56: ...ATION SUMMARY Instr Cal Date 01 Jun 2011 Instr Cal Time 15 03 Instr Cal Number 105 Cal Operator ID 39 Cal Kit Lot Code 39341 Cal Temperature 21 2 C Calibration Result Pass Instrument Serial No 8282 Software Version PCS 7A2 203 ARTEL PCS PIPETTE CALIBRATION SYSTEM Patents USA 5492673 5298978 7772008 7791716 Europe EP0711404 EP0628157 Japan 2520852 ...

Страница 57: ... 2011 Last Instr Cal No 105 Instrument Serial No 8282 Software Version PCS 7A2 203 ________________________ ____________ Performed by Date ________________________ ____________ Reviewed by Date ARTEL PCS PIPETTE CALIBRATION SYSTEM Patents USA 5492673 5298978 7772008 7791716 Europe EP0711404 EP0628157 Japan 2520852 Your Lab s Name Date 01 Jun 2011 Time 15 18 PIPETTE CALIBRATION Pipette ID 67443 Ope...

Страница 58: ...16 10 20 09 Number of Data Points 10 Mean Volume 20 08 uL Absolute Inaccuracy 0 08 uL Relative Inaccuracy 0 41 Standard Deviation 0 043 uL Coef of Variation CV 0 21 Temperature 21 2 C Pipette Sample Volume 50 00 uL Sample Solution Range 2 SAMPLE VOLUME 1 50 16 2 50 07 3 50 12 4 50 21 5 50 08 6 50 12 7 50 26 8 50 18 9 50 09 10 50 22 Number of Data Points 10 Mean Volume 50 15 uL Absolute Inaccuracy ...

Страница 59: ... 2 n x x STD n i i Coefficient of Variation 100 x STD CV Inaccuracy 100 volume nominal volume nominal x INACC Combined Expanded Uncertainty of the mean k 2 n STD x ui U 2 2 2 Standard Relative Uncertainties for PCS Ranges 1 through 6 u1 0 5 u4 0 3 u2 0 4 u5 0 3 u3 0 3 u6 0 3 n is the number of data points ...

Страница 60: ...15A3356O This Page Intentionally Left Blank ...

Страница 61: ... 107 k 36 60 84 T 108 l 37 61 85 U 109 m 38 62 86 V 110 n 39 63 87 W 111 o 40 64 88 X 112 p 41 65 A 89 Y 113 q 42 66 B 90 Z 114 r 43 67 C 91 115 s 44 68 D 92 116 t 45 69 E 93 117 u 46 70 F 94 118 v 47 71 G 95 _ 119 w 48 0 72 H 96 120 x 49 1 73 I 97 a 121 y 50 2 74 J 98 b 122 z 51 3 75 K 99 c 123 52 4 76 L 100 d 124 53 5 77 M 101 e 125 54 6 78 N 102 f 126 55 7 79 O 103 g ...

Страница 62: ...15A3356O This Page Intentionally Left Blank ...

Страница 63: ...tter Note that the 4 and 6 keys are typematic that is their action will repeat as long as they are held down Three other keys can be used to speed up the letter selection Key Function 1 Moves the carat to the letter A 2 Moves the carat to the letter M 3 Moves the carat to the letter Z The 1 and 3 keys speed up the selection of letters near the beginning or the end of the alphabet respectively The ...

Страница 64: ...15A3356O This Page Intentionally Left Blank ...

Страница 65: ...9 9 32 17 17 630 8 8 34 16 16 709 7 7 36 15 15 810 6 6 38 14 14 945 5 5 41 13 13 1134 4 4 44 12 12 1417 3 3 48 49 11 11 1889 2 2 5000 1 1 Range 4 2 22 40 60 mL Bottle 3 22 37 2 9 μL 4 22 28 Range 2 50 22 40 5 22 22 60 mL Bottle 59 22 39 6 18 18 50 199 μL 61 22 38 7 16 16 63 22 37 8 14 14 64 22 36 9 12 12 66 22 35 9 9 11 11 68 22 34 70 22 33 Range 5 0 5 22 40 72 22 32 60 mL Bottle 0 6 22 37 74 22 3...

Страница 66: ...15A3356O This Page Intentionally Left Blank ...

Страница 67: ...pipette volumes 50 to 199 µL PCS 223 PCS R3 Sample Solution Sample Solution for Range 3 for pipette volumes 10 to 49 9 µL PCS 224 PCS R4 Sample Solution Sample Solution for Range 4 for pipette volumes 2 to 9 9 µL PCS 225 PCS R5 Sample Solution Sample Solution for Range 5 for pipette volumes 0 50 to 1 99 µL PCS 226 PCS R6 Sample Solution Sample Solution for Range 6 for pipette volumes 0 1 to 0 499 ...

Страница 68: ...15A3356O This Page Intentionally Left Blank ...

Результаты поиска

Содержание PCS 2

Отзывы:

Бренды по названию

Популярные бренды

Artel PCS 2, Руководство по процедурам

Результаты поиска

Содержание PCS 2

Отзывы:

Бренды по названию

Популярные бренды