SPECTRONIC 20+ and SPECTRONIC 20D+
Contents
1. A A Because of the functional design and reliability of the SPECTRONIC 20 and SPECTRONIC 20D spectrophotometers routine customer maintenance has been reduced to replacement of the 6 0 volt 3 00 amperes source lamp The source lamp has a nominal life of 250 hours a The user may also perform routine checks for wavelength calibration and photometric accuracy The lamp gets very hot during operation Before removing the lamp turn off the instrument and allow the lamp to cool down for 10 minutes Turn off and unplug the instrument before removing the lamp door 1 Turn off and unplug the instrument 2 Tilt up the unit and set it on its back 3 Loosen the thumbscrew on the lamp access door and open the door see the Bottom view 4 Using finger pressure press the lamp flange toward the mounting bracket SPECTRONIC 20 and SPECTRONIC 20D User Guide 17 Lamp Lamp socket Mounting bracket Locating pins 1 2 3 4 Lamp flange 5 6 Terminals A Warning Do not touch the lamp with your fingers a 5 Push the lamp toward the lamp socket and rotate counterclockwise to remove it To avoid getting skin oils on the surface of the lamp use a dry clean cloth to grip the lamp 6 Install a new lamp by properly aligning the large openings in the lamp flange with the locating pins 7 Press the lamp and the lamp socket toward each other and rotate the lamp clockwise until secure 8 Clean the lamp of fingerpri2. 0 100 and 1000 Press the MODE control key to select the CONCENTRATION mode Rinse and fill the cell with the sample solution of unknown concentration Wipe the cell with a tissue and insert the cell in the sample comp artment Read the concentration of the sample directly from the display Remove the cell from the sample compartment and repeat steps 5 through 7 for each of the samples When all measurements are completed turn off the spectrophotometer by turning the Power Switch counterclockwise until it clicks For SPECTRONIC 20D only a Normally the spectrophotometer is in the print mode when it is first turned on and operates at a rate of 1200 baud A range of other transmission rates from 110 to 9600 baud may also be accommodated see Baud rate settings section 1 Set the baud rate on the Accessory Printer to 1200 2 Push the PRINT key for a printout 10 SPECTRONIC 20 and SPECTRONIC 20D User Guide Thermo Fisher Scientific Command set Thermo Fisher Scientific An external device may send the commands listed in the following table Convention Function Word length 8 data bits 1 stop bit most significant bit set to 0 Parity None Echo None Terminators Ignores all carriage return or line feed characters sent by external device except for CR in Auto Baud Rate mode Transmits ASCII CR LF after every data line The following table lists conventions for serial I O data C
3. 25 Problem Instrument does not function Troubleshooting The following table outlines some diagnostic techniques that may help you isolate the cause of a problem Possible Cause Power line cord not connected to outlet Dead power outlet Internal fuse blown Defective electronic component Possible Solution Plug in the power line cord Try a different power outlet Refer to service manual or service center Refer to service manual or service center Meter Display does not zero Sample compartment cover not closed Lamp access door not tightly closed Phototube defective Defective electronic component Close cover Close door and retighten thumbscrew Replace as required Refer to service manual or service center Readings are drifting or incorrect Thermo Fisher Scientific Poor sampling technique Filter selection lever is in wrong position Fumes from sample Excessive line voltage variation Wrong line voltage setting international models only Source lamp defective Phototube defective Defective electronic component Eliminate bubbles or particles in solution Set 100 T on appropriate blank solution Set filter lever to proper position Remove sample immediately after analysis Check voltage and grounding Reset line Voltage Selection Switch Replace with new lamp Replace as required Refer to service manual or service center SPECTRONIC 20 and SPECT
4. TXD Receive data RXD Print oorwhNh SPECTRONIC 20 and SPECTRONIC 20D User Guide 3 Installation and Operation This chapter provides important information about using your instrument to analyze samples Setup and Installation A Caution Ifthe equipment is not used in a manner not specified by the manufacturer the protection provided by the equipment may be impaired a 1 Select the appropriate glassware and adapters For more information about glassware adapters and cell holders refer to the Accessories section If you are connecting the instrument to an accessory printer computer or chart recorder refer to the following table for information about cabling requirements Device 20 20D Analog recorder Patch cord Patch cord Accessory printer Not available Serial interface cable kit PC Not available Serial interface cable kit 2 Plug the power cord into a grounded outlet with the appropriate voltage 3 Turn the Power Switch Zero Control clockwise and allow the instrument to warm up for at least 15 minutes Thermo Fisher Scientific SPECTRONIC 20 and SPECTRONIC 20D User Guide 4 Technique Sample measurements SPECTRONIC 20 Thermo Fisher Scientific Note Note Successful use of your spectrophotometer depends on the consistent use of correct laboratory procedures and analytical techniques To minimize problems follow these simple rules Keep all solutions free of bubbles Make sure that
5. display Every time new standard solutions are used for the same test such as for a new reagent batch or when setting up the instrument press the MODE select control until the FACTOR LED lights and note the factor on the digital display A change in the factor indicates a change in the slope of the standard curve due to variation in operating conditions It is recommended that a standard always be used to set the concentration mode The operator may choose however to set the blank to 000A then switch to the concentration mode SPECTRONIC 20 and SPECTRONIC 20D User Guide 15 Maintenance The information given in this section deals only with those parts of maintenance or service that can be safely carried out by the user Work other than that detailed should be carried out by our trained service engineer Cleaning instrument exterior he exterior and sample compartment of the instrument can be cleaned P P periodically as follows A Caution Do not allow moisture to leak into the instrument a 1 Switch off the spectrophotometer and disconnect from AC power source 2 Using a lint free cloth dampened with a weak solution of detergent and water wipe the exterior surface of the instrument as necessary 3 Wipe over with a cloth dampened with plain water 4 Dry the surface with another cloth 16 SPECTRONIC 20 and SPECTRONIC 20D User Guide Thermo Fisher Scientific Lamp Replacement Thermo Fisher Scientific Note
6. ASE KEA EEI PASEK ESTRAE T 10 Command setertireranenen a i a ea 11 Data format icsanicaiinni shen krea E e a Ae 12 Choosing a Readout Mode essessessessesoeseossossessesoesoesoesossosseseesoesessossees 13 Transmittance TOC E ictdea sa thas a1secechaaga aaan aaa a aaraa aat 13 PDSOE DANCE TOMS a E ARANA 13 Concentration Mode sssseesseeseeeesessreeerresseresetssresseressrresersseessreeseressees 14 Concentration Factor Check feature c ccccscscssscssssscesssscesssscsscscossesens 15 Main tem aince niesieni oeseri iaa aa aa LO Cleaning instrument exterior s seseeesesistetststststsrerststetststststsestsesesesesesee 16 Lamp Replacement e niseni ii a E E E E gs 17 Cleaning the sample compartment x33 Seas Ravine eee 19 Weavelenothcalibrationcheck 122 2 toca fy cee teen lta heen aac 21 Cobalt sol tion check neruecn nensi Raai i 21 Wavelength calibration adjustment ssssssessssssssssssesrseresrrrerereeerseseeees 22 Photometric linearity chee c cass sczecasievse sacbotcucssnoquavelsnesecutesyaaevateoeeeamasee 23 Service proceditie ssni ited cent dea ated RRE ieia 25 i Troubleshooting scceccicicscccseicetcsceicecenaeseaenudescorsnceausoandsscacscssaevenssbessetecs 20 Optical Ditagtanitss ts sictsceusdesiel sasstiascceveiats serieen a tera irei 2O SPECTRONIC 20 and SPECTRONIC 20D User Guide i ii SPECTRONIC 20 and SPECTRONIC 20D User Guide Thermo Fisher Scientific Introduction The SPECTRONIC 20 a
7. IC 20 and SPECTRONIC 20D User Guide 27 Optical Diagram TUNGSTEN LAMP ENTRANCE SLIT ee ele LENS LENS ios j FR as ie a ik Se nD a cad er EXIT SLIT GRATING CENTER OF TEST TUBE VARIABLE STOP FILTERS 100 T ADJUSTMENT PHOTODETECTOR Thermo Fisher Scientific SPECTRONIC 20 and SPECTRONIC 20D User Guide 28
8. RONIC 20D User Guide 26 Problem Cannot set 100 T 0 0A or display flashes Possible Cause 100 T not properly set Filter selection lever in wrong position 0 T not properly set all models except SPECTRONIC 20D Occluder closed Sample holder not fully inserted into adapter Source lamp weak or burned out Wrong line voltage setting international models only Phototube weak Error in wavelength calibration Defective electronic component Possible Solution Set 100 T with blank solution in the sample compartment and cover closed Several turns of the 100 T control may be necessary Set filter lever to proper position Set 0 T with the sample compartment empty and the cover closed Install test tube in sample compartment Insert fully Replace with new lamp Reset Line Voltage Selection Switch Replace as required Check calibration Refer to service manual or service center Readings are not repeatable even though the 0 T and 100 T readings are set correctly Thermo Fisher Scientific Loose lamp Loose sample holder adapter Poor analytical technique Test tube position not repeating Tighten thumbscrew on lamp access door Tighten set screw inside adapter Clean or replace dirty test tubes remove bubbles etc See Technique section Always position fiducial line in exactly the same place when test tube is inserted into adapter Use square cuvettes SPECTRON
9. SPECTRONIC 20 and SPECTRONIC 20D User Guide SCIENTIFIC The information in this publication is provided for reference only All information contained in this publication is believed to be correct and complete Thermo Fisher Scientific shall not be liable for errors contained herein nor for incidental or consequential damages in connection with the furnishing performance or use of this material All product specifications as well as the information contained in this publication are subject to change without notice This publication may contain or reference information and products protected by copyrights or patents and does not convey any license under our patent rights nor the rights of others We do not assume any liability arising out of any infringements of patents or other rights of third parties We make no warranty of any kind with regard to this material including but not limited to the implied warranties of merchantability and fitness for a particular purpose Customers are ultimately responsible for validation of their systems 2007 Thermo Fisher Scientific Inc All rights reserved No part of this publication may be stored in a retrieval system transmitted or reproduced in any way including but not limited to photocopy photograph magnetic or other record without our prior written permission For Technical Support please contact Thermo Fisher Scientific 5225 Verona Road Madison WI 53711 4495 U S A T
10. Select Factor Adjust controls Print Analog Output Serial 1 0 port Function This control sets the display to 100 T 0 0A when a cell containing a blank reference solution is inserted in the sample compartment It must be reset whenever the analytical wavelength has been changed When operating at a fixed wavelength for an extended period of time check the 100 T 0 0A readout and readjust if necessary This control selects the TRANSMITTANCE ABSORBANCE CONCENTRATION or FACTOR mode The push buttons labeled INCREASE and DECREASE are used in the CONCENTRATION and FACTOR modes To set a lower CONCENTRATION or FACTOR value press and hold down the DECREASE button until the desired value is displayed To set a higher value press and hold down the INCREASE button until the desired value is displayed This push button is used to send data to a serial printer or an external device connected to the output jack Analog output This port is used to connect an analog recorder to the instrument The analog output signal level is approximately 1 VDC at 100 T This output is not adjustable Serial port The Serial Input Output 1 0 Port is used to connect the instrument to the accessory printer or to an external device enabling the instrument to accept and execute any one of six commands sent from the device in RS232C format The signals on each pin are listed below Analog output Clear to sent CTS Ground Transmit data
11. all sample holders are at least half full Use the same cell for both sample and blank measurements Use square cells with holder for greater accuracy Make sure that the mark fiducial line on the test tube aligns with the mark on the adapter toward the front of the instrument During extended operation at a fixed wavelength check from time to time for 100 T drift Possible causes of drift are listed in the Troubleshooting section Use clean test tubes and do not touch the test tubes below the fiducial line Once your instrument has been set up properly and has warmed up for at least 15 minutes you can begin taking measurements To read the meter properly align the needle with its reflection in the mirror a It is important to insert the blank and reset the meter to 100 T every time the wavelength is changed a 1 After the warmup period set the desired wavelength with the Wavelength Control Knob Set the filter lever to the appropriate position for the selected wavelength SPECTRONIC 20 and SPECTRONIC 20D User Guide 5 10 11 12 13 14 Adjust the meter to 0 T with the Power Switch Zero Control knob on the front left side of instrument Make sure the sample compartment is empty and the cover is closed Fill a clean cell with water or blank solution and wipe the cell with a tissue to remove liquid droplets dust and fingerprints Place the cell in the sample compartment and align the
12. band Black graphical symbol inside a red circular band with a red diagonal bar White graphical symbol inside a blue circle Black graphical symbol inside a yellow triangle with a black triangular band White graphical symbol inside a blue circle Indication This is a warning symbol The graphic in this symbol is used to alert the user to potential hazards This is a prohibition symbol The graphic in this symbol is used to alert the user to actions that shall not be taken or shall be stopped This is a mandatory action symbol It is used to indicate that an action shall be taken to avoid a hazard This is the general warning sign Failure to heed the safety precautions could result in personal injury This is the general data loss or property damage symbol and is not related to personal injury Failure to heed these precautions can result in irreparable damage to property or permanent data loss In case of emergency follow the procedures established by your facility If you have questions or concerns about safety or need assistance with operation repairs or replacement parts you can contact our sales or service representative in your area or use the information at the beginning of this document to contact us 2 SPECTRONIC 20 and SPECTRONIC 20D User Guide Thermo Fisher Scientific Spectrophotometer Basics This spectrophotometer series was designed to meet the needs of a wide range of routine
13. button a 12 SPECTRONIC 20 and SPECTRONIC 20D User Guide Thermo Fisher Scientific Choosing a Readout Mode Transmittance mode All SPECTRONIC 20 series spectrophotometers measure the relative amount of light transmitted yielding results in transmittance The transmittance mode is useful for calibration stray radiant energy tests and filter studies Furthermore very low concentrations may be measured with greater sensitivity in the transmittance mode When the transmittance mode is used the reagent blank sets 100 T and the results for standard solutions and unknown samples are obtained as percent transmittance A standard curve may be constructed on semi logarithmic paper by plotting the percent transmittance on the logarithmic axis vs the concentration of known standard solutions on the linear axis The best line is drawn through these points The concentration of unknown samples may then be determined by locating the concentration value which corresponds to the percent transmittance of the unknown on the standard curves Absorbance mode Usually the operator desires results in absorbance for direct correlation of concentration by Beer s law A abc Results in percent transmittance may be converted to absorbance values by use of transmittance absorbance conversion tables or by the formula A logioT Results in absorbance may be plotted against the concentration of known standards on rectilinear graph paper The best lin
14. cessories Thermo Fisher Scientific Glassware selection and sampling options In addition to the standard 12 in test tube and in adapter supplied with the instrument several types of glassware are available The sample adapter must match the glassware To change adapters loosen the small set screw on the inner wall of the adapter using the adapter wrench clipped to the bottom of the instrument The design of the standard adapter provided with the instrument was changed in 1986 The current adapter accommodates a 2 in diameter test tube or a 2 in square cell Prior to 1986 the standard adapter accommodated only the 2 in diameter test tube To identify the standard adapter easily turn the adapter bottom end up and look into the barrel of the adapter The image below illustrates the pre 1986 design which will not accommodate a 2 in square cell This can be replaced with a current adapter to accommodate 2 in square cells Key 1 Spring found in pre 1986 adapters SPECTRONIC 20 and SPECTRONIC 20D User Guide 1 Operating features of SPECTRONIC 20 The main controls for routine operation are the Power Switch Zero control Wavelength control Filter lever and Transmittance Absorbance control Control Power Switch Zero control Wavelength control Filter lever Meter Transmittance Absorbance control Thermo Fisher Scientific Function The ON OFF main power switch is operated by the Power Swi
15. e is drawn through these points to construct a standard curve The concentration of unknowns may then be determined by locating on the standard curve the concentration value which corresponds to the absorbance of the unknown Thermo Fisher Scientific SPECTRONIC 20 and SPECTRONIC 20D User Guide 13 To eliminate T to A calculations each model of the instrument provides conversion of transmittance to absorbance e The SPECTRONIC 20 has an absorbance scale marked with values corresponding to percent transmittance The operator may simply read the absorbance scale and use these values to construct a standard curve as described above e The SPECTRONIC 20D offers precise electronic conversion of transmittance to absorbance When the absorbance mode is used the reference blank sets 0 000A and the results for standards and unknowns are obtained in absorbance Results in absorbance may be related to concentration by Beer s law A abc if the absorptivity and pathlength are known or by constructions of a standard curve as described above Absorbance measurements are useful for kinetics studies and for reaction systems which do not obey Beer s law and therefore have non linear standard plots Concentration Mode The SPECTRONIC 20D provides a more convenient readout the concentration mode which eliminates the necessity for constructing a standard curve The instrument electronically converts results in absorbance to concentratio
16. elephone 1 800 532 4752 E mail us techsupport analyze thermofisher com World Wide Web http www thermo com spectroscopy For International Support please contact Thermo Fisher Scientific Telephone 1 608 273 5017 E mail support madison thermofisher com World Wide Web http www thermo com spectroscopy All trademarks are the property of Thermo Fisher Scientific Inc and its subsidiaries 269 219200 Rev A Thermo Fisher Scientific Contents Tint GU CEG INisesidiansonsdevitannn cvasaeencvbienisoxinsnseeviiasisevicapaneviduriesvinsunasdahantaese L Conventions used in this manual 0 eeeeeeeessecccecececeessssnaccececeeecesssnenacees 1 Questions OF COMCELDS s sussncdsiugscdeeancdustivagtacdounsededuevupscedvsaddeveoen ENE KET NS 2 Spectrophotometer Basics e sessesseseesoesoesosseseesoesoesossosseseesoesoesossossosseseese L Spectrophotometer COoMponentsS s ssessssssssesesrsrstststststststsesesestsesesesesesese 1 ACCESSOTIES arhont ratere T EA EEE gs E OaE REAS eT 1 Operating features of SPECTRONIC 20 sssssssssesssessssssrseersesesesssessese 1 Operating features of SPECTRONIC 20D seccassecscerensevoratvacsteteseteceanetates 2 Installation and Operation ssessesessossossesseseeseesoesossosseseesoesoossosseseeseeseesess Setup and Install tioh siirat ingarsa esser 4 Technique sanan tient ila ease AE E AEA 5 Sample iieas remMmeEn tsienen een T s E E atte niles 5 PENINE oiea st Eaa ESEA SEn EsAN LE
17. ground Analog ground Analog output Fon Operating features of SPECTRONIC 20D The main controls for routine operation are the Power Switch Zero control Wavelength control Filter Lever Transmittance Absorbance control the MODE selector and Factor Adjust controls The accessory Analog Output Serial I O port is located on the underside of the instrument as shown in the Bottom view above Control Function Power Switch Zero control The ON OFF main power switch is operated by the Power Switch Zero control knob The Zero control knob is used to set the display to a 0 T readout when the sample compartment is empty and the adapter cover is closed Wavelength control The Wavelength control selects the desired analytical wavelength of the instrument The selected wavelength appears on the left side of the LED display The Filter lever should be set to the proper filter for the wavelength setting Filter lever This control selects the filter to be used for the measurement The proper lever position for the set wavelength is indicated on the label above the lever Digital Readout The Digital Readout displays wavelength and data readings The four LED status indicators next to the labels TRANSMITTANCE ABSORBANCE CONCENTRATION and FACTOR indicate the MODE currently active 2 SPECTRONIC 20 and SPECTRONIC 20D User Guide Thermo Fisher Scientific Thermo Fisher Scientific Control Transmittance Absorbance control MODE
18. guide mark on the cell with the guide mark at the front of the sample compartment Press the cell firmly into the sample compartment and close the lid Adjust the meter to 100 T with the Transmittance Absorbance Control knob on the front right side of instrument Remove the cell from the sample compartment and empty the water Rinse the cell twice with small volumes of the solution to be measured and fill it with the solution Wipe the cell with a tissue and insert the cell into the sample compartment Align the guide marks and close the lid Read the appropriate value T or A from the meter Remove the cell from the sample compartment and repeat steps 10 through 13 for any remaining sample solutions When all measurements are completed turn off the spectrophotometer by turning the Power Switch Zero Control counterclockwise until it clicks 6 SPECTRONIC 20 and SPECTRONIC 20D User Guide Thermo Fisher Scientific SPECTRONIC 20D Note Note Transmittance and Absorbance Thermo Fisher Scientific A flashing display indicates that the reading is out of range and the 100 T 0A control must be adjusted This adjustment controls an optical occluder which regulates the amount of light passing through the sample In T mode A reading of greater than 200 T will cause the display to flash e Ifthe flashing reading is 1999 turn the 100 T 0A control clockwise until the display operates normally e Ifthe flashing reading
19. h a tissue to remove liquid droplets dust and fingerprints Place the cell in the sample compartment and align the guide mark on the cell with the guide mark at the front of the sample compartment Press the cell firmly into the sample compartment and close the lid Adjust the display to 100 T or 0 0A with the Transmittance Absorbance Control knob on the right side of instrument Remove the cell from the sample compartment and empty the water Rinse the cell twice with small volumes of the solution to be measured and fill it with the solution Wipe the cell with a tissue and insert the cell into the sample compartment Align the guide marks and close the lid Read the appropriate value T or A from the display Remove the cell from the sample compartment and repeat steps 11 through 14 for any remaining sample solutions When all measurements are completed turn off the spectrophotometer by turning the Power Switch counterclockwise until it clicks 8 SPECTRONIC 20 and SPECTRONIC 20D User Guide Thermo Fisher Scientific Concentration measurements using CONCENTRATION mode Thermo Fisher Scientific Note 1 Follow steps 1 through 9 of the Transmittance and Absorbance procedure using the Absorbance mode Rinse the cell twice with small volumes of the standard solution of known concentration and fill the cell with the solution Wipe the cell with a tissue and insert the cell in the sample compartment Al
20. ign the guide marks and close the lid Press the MODE control key until the LED beside concentration is lit Press the INCREASE or DECREASE key until the displayed value matches the concentration of the standard solution Limits are 0 to 1999 a 7 10 11 12 13 To determine the factor press the MODE control key until the LED beside the Factor is lit Read and record the factor value Press the MODE control key until the LED beside Concentration is lit Remove the standard solution and rinse and fill the cell with the sample solution of unknown concentration Wipe the cell with a tissue and insert the cell in the sample compartment Read the concentration of the sample directly from the display Remove the cell from the sample compartment and repeat steps 9 through 11 for each of the samples When all measurements are completed turn off the spectrophotometer by turning the Power Switch counterclockwise until it clicks SPECTRONIC 20 and SPECTRONIC 20D User Guide 9 Concentration measurements using FACTOR mode Printing Note Note Refer to Choosing a Readout Mode section for more information about the FACTOR mode a Determine the factor value by following steps 1 through 4 of the procedure for CONCENTRATION mode above Press the MODE control key until the LED beside factor is lit Press the INCREASE or DECREASE key until the desired factor is displayed a value between
21. is 1999 turn the 100 T 0A control counterclockwise until the display operates normally In absorbance mode A reading of greater than 2A will cause the display to flash e Ifthe flashing reading is 1999 turn the 100 T 0A control counterclockwise until the display operates normally e Ifthe flashing reading is 1999 turn the 100 T 0A control clockwise until the display operates normally It may require several complete turns of the 100 T control to return to the proper range a Change in wavelength it is important to insert the blank and reset the display to 100 T or 0 0A every time the wavelength is changed a 1 Turn on the instrument by turning the Power Switch knob on the left side of instrument clockwise Allow the spectrophotometer to warm up for at least 15 minutes to stabilize 2 After the warmup period set the desired wavelength with the Wavelength Control knob SPECTRONIC 20 and SPECTRONIC 20D User Guide 7 10 11 12 13 14 15 16 Set the filter lever to the appropriate position for the selected wavelength Adjust the display to 0 T with the Zero Control knob on the front left side of the instrument Make sure that the sample compartment is empty and the cover is closed Set the display mode to TRANSMITTANCE or ABSORBANCE by pressing the MODE control key until the appropriate LED is lit Fill a clean cell with water or another blank solution and wipe the cell wit
22. ld be within 0 02A of the expected absorbance values if the solutions have been prepared carefully a 24 SPECTRONIC 20 and SPECTRONIC 20D User Guide Thermo Fisher Scientific Service procedure Thermo Fisher Scientific If the instrument develops a malfunction that cannot be corrected by operator maintenance it may be serviced by your local sales or service organization If you are in the U S A contact technical support whether the instrument is still under warranty or is past the warranty period If you are outside the U S A contact the distributor from whom you purchased the instrument whether the instrument is still under warranty or is past the warranty period If it is necessary to ship the instrument 1 Wrap the spectrophotometer in plastic and then pack carefully in a crush resistant carton with at least three inches of shock absorbing material to prevent transit damage Include a detailed letter inside the shipping carton fastened to the instrument describing the trouble Please include the name and phone number of the person or department head most familiar with the problem This information enables service personnel to make required repairs promptly and at least expense In the United States mark on the shipping container FIRST CLASS LETTER ENCLOSED First class postage is required only on the letter The carton is accepted at standard mail rates SPECTRONIC 20 and SPECTRONIC 20D User Guide
23. led water 2 Slowly and cautiously add 10mL concentrated hydrochloric acid ACS grade 3 Mix and make to volume with distilled water to obtain 1 hydrochloric acid solution 4 Ina 1 liter volumetric flask place 22 to 23 gm cobalt chloride CoCI2 ACS grade 5 Dissolve in the 1 hydrochloric acid 6 Dilute to volume with 1 hydrochloric acid to obtain cobalt chloride stock solution To perform the cobalt solution check 1 Turn on the Power Switch Zero Control and allow the instrument to warm up for at least 15 minutes SPECTRONIC 20 and SPECTRONIC 20D User Guide 21 2 Ifyou have a SPECTRONIC 20D set the display mode to Transmittance 3 With the sample compartment empty and the cover closed adjust the Power Switch Zero Control until the meter or display reads O T 4 Set the Wavelength Control to 500 nm 5 Set the Filter Lever to 340 599 nm 6 Insert the glassware filled with distilled water into the sample compartment and use the Transmittance Absorbance Control to set the meter or display to 100 T 7 Replace the distilled water with the cobalt chloride solution 8 Insert the glassware filled with the cobalt chloride solution into the sample compartment 9 Read T on the meter or display 10 Repeat steps 4 through 9 at 505 510 515 and 520 nm The instrument is in proper calibration when minimum transmittance maximum absorbance occurs between 505 and 515 nm The specific transmittance
24. n the lamp filter or photodiode surfaces Lamp and filter surfaces Clean with a soft cloth or the softest area of a cotton swab and glass cleaner Photodiode The photodiode is easily damaged therefore cleaning should be performed by our service organization Clean the photodiode only if liquid is spilled on it Use very light pressure with the softest area of a cotton swab dipped in high grade isopropyl alcohol Do not touch the wire connected to the detector 9 Close the door and tighten the thumbscrew 10 Check the calibration of the instrument using the procedures below or call technical support if necessary 20 SPECTRONIC 20 and SPECTRONIC 20D User Guide Thermo Fisher Scientific Wavelength calibration check Cobalt solution check Thermo Fisher Scientific Under normal operating conditions the SPECTRONIC 20 and SPECTRONIC 20D spectrophotometers should retain their wavelength accuracy indefinitely If the instrument is subjected to a severe shock or other abuse wavelength performance may be checked by one of three methods 1 Cobalt solution check 2 Didymium filter from the accessory filter kit 3 Wavelength Accuracy Test from SPECTRONIC Standards An explanation of the cobalt solution check follows Instructions on use of the didymium filter and SPECTRONIC Standards are found in the user s manual for each accessory To prepare a stock cobalt solution 1 Ina 1 liter volumetric flask place 200 ml distil
25. n units by multiplying the absorbance value by the factor which is the inverse of the slope of the standard curve factor 1 ab Note that the concentration mode can be used only if the linearity of the standard curve has been verified for the test conditions used These test conditions include wavelength concentration range of interest cell pathlength and analytical procedure Furthermore the concentration mode may be used only if the standard curve has a positive slope i e absorbance increases with concentration When using entered standard solutions the 1 ab factor is used to convert absorbance to concentration according to the equation C f A 14 SPECTRONIC 20 and SPECTRONIC 20D User Guide Thermo Fisher Scientific Note The Concentration Measurements using FACTOR mode describes how to use the factor mode It is not actually necessary to know the 1 ab factor because this factor is introduced into the instrument when the concentration adjust control is used to set the digital display to read the concentration of the standard a Concentration Factor Check feature Thermo Fisher Scientific To verify that operating conditions do not vary between reagent batches or from day to day use the concentration factor check features as follows After the concentration mode has been set up with standard solutions press the MODE select control until the FACTOR LED lights and read and record the factor given on the digital
26. nd SPECTRONIC 20D are single beam spectrophotometers Durable and easy to use the 20 series is ideal for a student laboratory as well as for simple QC and water analysis laboratories This manual describes the spectrophotometer and how to use it You will find everything from specifications for the instrument to routine maintenance procedures In addition to this manual you also received a box of 1 2 inch test tubes and a 2 inch adapter with your spectrophotometer The adapter is already installed so the instrument is ready to use Conventions used in this manual Thermo Fisher Scientific Note Notice A Caution A Warning A Danger This manual includes safety precautions and other important information presented in the following format Notes contain helpful supplementary information a Follow instructions labeled Notice to avoid damaging the system hardware or losing data a Indicates a hazardous situation which if not avoided could result in minor or moderate injury a Indicates a hazardous situation which if not avoided could result in death or serious injury A Indicates a hazardous situation which if not avoided will result in death or serious injury A SPECTRONIC 20 and SPECTRONIC 20D User Guide 1 Questions or concerns The following safety symbols may be used on this product SP e oD Description Black graphical symbol inside a yellow triangle with a black triangular
27. nts and oils close the door and tighten securely This is essential for proper operation 18 SPECTRONIC 20 and SPECTRONIC 20D User Guide Thermo Fisher Scientific Note Do not push on the lamp socket terminals This will inhibit the installation of a new lamp a Cleaning the sample compartment Turn off and unplug the instrument before cleaning the sample compartment In the event a test tube breaks in the sample compartment it is important to remove the glass and any spilled liquid as soon as possible 1 Turn off and unplug the instrument A Warning Use protective equipment safety goggles gloves lab coat etc a 2 Thermo Fisher Scientific Using tweezers remove broken pieces of glass from the sample compartment While supporting the instrument move it to the edge of the lab bench so that the lamp access door may be opened Loosen the lamp access door thumbscrew and carefully open the door Spilled fluid may be present inside Make sure to clean up all liquid that was spilled Reach inside the lamp compartment and remove any remaining glass Tip the instrument back on the lab bench and clean the sample compartment with an appropriate cleaning solvent Visually inspect the lamp photodiode and filters to determine if any liquid has spilled on them SPECTRONIC 20 and SPECTRONIC 20D User Guide 19 Sl or Key 1 Photodiode 2 Connection wire 3 Lamp 4 Filter 8 Remove any liquid spilled o
28. ommand P A c F Control X E or an ASCII carriage return CR Function Print Set the data mode to absorbance Set the data mode to transmittance Set the data mode to concentration Set the data mode to factor Reset the spectrophotometer to initial power up condition Set the spectrophotometer s baud rate to the rate used by a computer connected to the serial output port SPECTRONIC 20 and SPECTRONIC 20D User Guide 11 Data format Data from the instrument to a printer or other remote device is sent as shown in the following example 574NM 01 5 A CR amp LF 3 digits for WVL Carriage return and then NM line feed Data type Space T T C or F Sign Blank or Space Data 3 digits plus a decimal point Baud rate settings Data is sent to the printer or received from an external device at a rate of 1200 baud if the instrument is turned on with the PRINT line high at logic 1 greater than 2 0 VDC Other baud rates may be selected when the spectrophotometer is connected to a computer These rates include 110 300 1200 2400 4800 and 9600 baud If the spectrophotometer is turned on with the PRINT line low logic 0 less than 0 8 VDC it adjusts to the computer s baud rate upon receipt of either the letter E or a carriage return CR character from the computer Note The PRINT line is normally high The PRINT line can be set low by pressing the PRINT
29. or absorbance values are unimportant Wavelength calibration adjustment If the wavelength accuracy is out of tolerance refer to the Service Procedure section Customer recalibration is not recommended 22 SPECTRONIC 20 and SPECTRONIC 20D User Guide Thermo Fisher Scientific Photometric linearity check Thermo Fisher Scientific If the photometric linearity of the instrument is questionable first check your analytical procedure and technique see the Technique section above If proper operation is still in doubt use the Photometric Accuracy Linearity Test from SPECTRONIC Standards to test and evaluate photometric performance of your instrument The alternate method below uses specially prepared potassium dichromate solutions 1 Turn on the Power Switch Zero Control and allow the instrument to warm up for at least 15 minutes 2 Make sure that the sample compartment is empty and the cover is closed then adjust the Power Switch Zero Control until the display reads O T 3 Ifyou have a SPECTRONIC 20D set the display mode to Absorbance 4 Prepare 0 01N sulfuric acid diluent by adding 0 3 ml of concentrated sulfuric acid to about 500 ml of deionized or distilled water in a clean 1 liter volumetric flask 5 Fill to volume with deionized or distilled water 6 Prepare a stock solution of potassium dichromate by weighing 0 500 g of potassium dichromate e g Fisher Certified A C S potassium dichromate formula weigh
30. spectrophotometric analyses As a basic laboratory instrument it provides reliable and repeatable results The SPECTRONIC 20 has an analog meter readout The SPECTRONIC 20D has an LCD digital display Both models have an overall wavelength range of 340 nm to 950 nm and a nominal spectral bandwidth of 20 nm consistent over the entire wavelength range Spectrophotometer components Thermo Fisher Scientific The following illustrations identify some major components visible on the outside of a typical SPECTRONIC 20 series SPECTRONIC 20 and SPECTRONIC 20D User Guide 1 SPECTRONIC 20 NN KR WON 2 SPECTRONIC 20 and SPECTRONIC 20D User Guide Sample compartment Pilot lamp Wavelength control Transmittance Absorbance control 100 T 0A Power switch Zero control Filter lever Thermo Fisher Scientific SPECTRONIC 20D UD QD A Q SS Sample compartment Digital readout Mode indicators Mode selection Decrease Increase Print Wavelength control Transmittance Absorbance control 100 T 0A Power switch Zero control ee a ne ay ee T p Filter lever Thermo Fisher Scientific SPECTRONIC 20 and SPECTRONIC 20D User Guide 3 Bottom view Key 1 Lamp access door with thumbscrew 2 Filter lever 3 Analog output jack Serial I O port 4 Line voltage switch under this plate international models only 4 SPECTRONIC 20 and SPECTRONIC 20D User Guide Thermo Fisher Scientific Ac
31. t 294 19 and dissolving it in about 400 ml of 0 01N sulfuric acid solution in a 500 ml volumetric flask 7 Fill to volume with 0 01N sulfuric acid solution This is your stock 1 0g l potassium dichromate solution 8 Measure 2 5 ml of the stock 1 0g l potassium dichromate solution into a clean 100 ml volumetric flask containing about 75 ml 0 01N sulfuric acid solution SPECTRONIC 20 and SPECTRONIC 20D User Guide 23 10 11 12 13 14 15 16 Fill to volume with 0 01N sulfuric acid solution This is your 0 025g I potassium dichromate solution Measure 5 0 ml of the stock 1 0 g l potassium dichromate solution into a clean 100 ml volumetric flask containing about 75 ml 0 01N sulfuric acid solution Fill to volume with 0 01N sulfuric acid solution This is your 0 05 g l potassium dichromate solution Set the Wavelength Control to 350 nm Set Filter Lever to 340 950 nm Fill a 10 mm pathlength rectangular cell with 0 01N sulfuric acid solution and place it in the sample compartment Set the readout of the instrument to 0A Fill the 10 mm pathlength rectangular cell with 0 025 g l potassium dichromate solution place it in the sample compartment and read the absorbance You should expect to read 0 248A Fill the 10 mm pathlength rectangular cell with 0 05 g l potassium dichromate solution place it in the sample compartment and read the absorbance You should expect to read 0 496A Note Values shou
32. tch Zero Control knob The Zero Control knob is used to set the display to a O T readout when the sample compartment is empty and the adapter cover is closed The Wavelength Control selects the desired analytical wavelength of the instrument The selected wavelength is indicated on the wavelength scale in the window next to the knob Red numbers indicate that the 600 950 nm lever position should be used Black numbers indicate that the 340 599 nm lever position should be used All graduations are in 5 nm intervals This control selects the filter to be used for the measurement The proper lever position for the set wavelength is indicated on the label above the lever Readings are taken directly from the meter in either transmittance or absorbance This control sets the display to 100 T 0 0A when a cell containing a blank reference solution is inserted in the sample compartment It must be reset whenever the analytical wavelength has been changed When operating at a fixed wavelength for an extended period of time check the 100 T 0 0A readout and readjust if necessary SPECTRONIC 20 and SPECTRONIC 20D User Guide 1 Control Function Analog output jack This jack is used to connect an analog recorder to the instrument see Bottom view above The analog output signal level is fixed at approximately 1 VDC at 100 T This output is not adjustable The signals on each pin are listed below Analog output Analog
Download Pdf Manuals
Related Search