BIC BI-200SM Instruction Manual Download Page 57 | Manualshive

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BIC BI-200SM Instruction Manual Download Page 57

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Summary of Contents for BI-200SM

Page 1: ...struction Manual for BI 200SM Goniometer Ver 2 0 Brookhaven Instruments Corporation 750 Blue Point Road Holtsville New York 11742 U S A Phone 631 758 3200 FAX 631 758 3255 e mail info bic com www bic...

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Page 3: ...r is on This will ruin the photomultiplier tube and void the warranty Align the system as described in the manual Brookhaven Instruments is not responsible for photomultiplier tubes ruined by ignoring...

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Page 5: ...translated into any human or computer language in any form or by any means electronic mechanical magnetic optical chemical manual or otherwise without the express written permission of Brookhaven Inst...

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Page 7: ...direct indirect incidental consequential or other types of damages resulting from the use of this product other than the liability stated above These warranties are in lieu of all other warranties ex...

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Page 9: ...ignal Connections 4 18 IV 6 Temperature ControL 4 19 IV 7 Filtration Circulation 4 22 V Sample Preparation 5 1 V 1 Dust 5 1 V 2 Filtration 5 2 V 3 Purification 5 4 V 4 Cell Cleaning 5 6 V 5 Solution S...

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Page 11: ...TABLE OF CONTENTS VIII Intensity Measurements Rayleigh Ratios 8 1 VIII 1 Corrections 8 1 VIII 2 Reference Intensity 8 3 VIII 3 Calibration 8 4 VIII 4 Rayleigh Ratios 8 5 VIII 5 Toluene Benzene 8 6 vi...

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Page 13: ...weight radius of gyration and second virial coefficient From the QELS measurements one calculates diffusion coefficients particle size and particle size distribution information The design of the BI...

Page 14: ...results Photon eorrelation spectroscopy PCS measurements are discussed in Section VI A more complete discussion of PCS measurements is found in Brookhaven corre lator manuals Intensity measurements ar...

Page 15: ...in integral amplifier discriminator The low voltage power requirements 5vdc are supplied from a Brookhaven correlator or photon counter A separate high voltage supply 1 500 to 3 00Ovdc 3mA 15mvdc for...

Page 16: ...f filters smooth tip forceps for handling filters Teflon tubing and connectors For use with most index matching fluids like toluene or decahydro napthalene trade name Decalin Temperature controller wi...

Page 17: ...200SM Goniometer SIN 80451 Detector Type BI DS1 PMT SIN HC1303 Dark Count Rate 275 25 cps 24 C OPTIONS Correlator Type PCI BI 9001 AT Di Correlator SIN 4001136 NOTES ORIGINAL PURCHASER Prof Sinha ORGA...

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Page 19: ...n ratio 1 33 Refractive Index of Sample Liquid 1 474 Refractive Index of Sample Cell 1 500 Refractive Index of Vat Liquid 1 474 Pinhole size 1 mm Polarization Analyzer None Interference Filter In Erro...

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Page 21: ...s such as the high voltage power supply and the filtration circulation system are packed separately in the large white box with the BIC logo The long carton contains the optical rail part ofthe laser...

Page 22: ...ALIGNMENT Page 4 2 Figure IV 1 Top Side View of Assembled Goniometer...

Page 23: ...r ofrotation adjustment screws Center ofrotation locking screw Center of rotation adjustment table Beam focusing and steering lens assembly Sample cell assembly Beam Stop Lens adjustment horizontal Le...

Page 24: ...uld not look directly at the laser beam in the following alignment procedures This manual refers to laser power of 15 mW or less CAUTION HIGHER POWER LASERS MAY CAUSE BRH SAFETY LIMITS FOR VIEWING OPT...

Page 25: ...ADIATION WHEN OPEN AVOID DIRECT EXPOSURE TO BEAM c 1mBROOKHAVEN INSTRUMENTS CORPORATION 7SO BLUE POINT ROAD HOLTSVILLE NEW YORK 11742 Manufactured April 1996 Model BI 200SM Serial No 400 Pow imW v THI...

Page 26: ...ignment procedure the laser shutter is opened and shut in a precise sequence to avoid directly viewing the laser beam It is difficult to judge the size and position ofvery bright beams Ifyour laser po...

Page 27: ...5 with the 2 mm aperture located on the opposite side ofthe goniometer from the laser rail and replace it with the detector rail 6 Fasten the rail to the rotating detector arm 4 using the two screws t...

Page 28: ...sed is not cylindrical remove the crossbar by unscrewing the knurled plastic topped screws located on the mount posts See Figure IV 5 Position the mounts and laser as far as possible from the goniomet...

Page 29: ...V 5 Optional Laser Mount BI LRM Crossbar Knurled plastic topp crews Vertical r L Adjustment ob Look underneath the center of rotation adjustment table 8 The table should be centered with an equal gap...

Page 30: ...ugh both apertures For most users who have not purchased cylindrical lasers vertical adjustments can be made by using the large knurled brass knob located in the center ofthe mount To correct for hori...

Page 31: ...lat toward zero degrees The band starts about 1 cm from the base ofthe vat When dry gently wipe this region by dragging a lens tissue across the surface ofthe vat onto which you have dripped reagent g...

Page 32: ...ptical reflection from the rear ofthe vat It is the spot that you want to superimpose on the input beam not the elliptical reflection Ifthe spot is not obvious to you then temporarily block the beam i...

Page 33: ...embly until the beam is vertically centered on the target The image on the target is now a vertical oval See Figure IV IO Figure IV 10 Image of Laser on Target With the needle tip well below the beam...

Page 34: ...orizontally as depicted in Figure IV 12 BLOCK THE LASER BEAM Figure IV 11 Image of Target for Lens Adjustments Here the laser is striking the side ofthe needle Notice the flare is on an angle The need...

Page 35: ...the eyepiece up and down until the slit is sharply in focus Lock down the eyepiece Rotate the mirror adjustment clockwise Slide the detector optic along the rail until it is 145 rom from the center o...

Page 36: ...ou will not be able to superimpose the light onto the center of the target like it is in Figure IV 14 At this point it is more important to get the image centered vertically Use adjustment 12B to acco...

Page 37: ...ser intensity image Change the angle 19 slightly until the maximum intensity is observed Repeat this process until the uniformly bright image is centered on the target Check the images using the other...

Page 38: ...ssembly is perfectly centered on the turntable the needle will appear to move across the slit B Use adjustment screw 7A to halve the distance the needle tip is displaced from the center ofthe slit Thi...

Page 39: ...le is out of the slit Move the slit 13A until the needle is centered After rotation to 155 the needle may look like this Halve the difference 7A Move the slit 13A until the needle is centered At 90 if...

Page 40: ...e not block the laser beam then carefully remove the brass manifold Unblock the laser beam and rotate and translate the vat until the reflection and image are correct Then replace the lens assembly Us...

Page 41: ...ce is necessary in systems where the PMT housing is longer than our standard It is not supplied unless the BI DS2 option is purchased Brookhaven s standard PMT and housing do not require additional su...

Page 42: ...ach the long gray coaxial cable supplied with LEMO connectors at both ends to either low voltage output of the correlator to the low voltage input on the tube This supplies the power to the amplifier...

Page 43: ...power supply has been preset at the factory to operate your PMT at peak performance Contact the factory ifyou need to change the HV setting Do not turn on the high voltage power supply at this time D...

Page 44: ...er Many standard temperature baths with external circulation capability are suitable The ones provided by BIC are typically capable ofregulating temperatures over a larger range than the sample cell a...

Page 45: ...the bath Instead of water use ethylene glycol antifreeze It is less corrosive and does not evaporate as easily A 50 vlv aqueous mixture is also suitable Use hose clamps on all I O ports The inside dia...

Page 46: ...ture change There is also a lag in time between thermal equilibrium ofthe circulator bath and the sample With circulators supplied by BIC it takes about 15 minutes for the sample to reach 40 0 C start...

Page 47: ...e used for a minute or two A filter change will also be required after the first few minutes BI FC Connections See Figure IV 20 Attach tube 3 to one of the Teflon elbow connectors Insert the tube unti...

Page 48: ...housing Wet the prefilter and place it with its smooth side against the filter Center it as best you can this will help prevent leakage To seal the filters inside tighten the housing with the wrenches...

Page 49: ...ust is visible Check for leaks Tighten connections until the leaks stop With the pump stopped the filter holder may be opened for filter replacement Ifthe amount ofdust is not noticeably reduced after...

Page 50: ...ALIGNMENT Page 4 30...

Page 51: ...TARGET ALIGNMENT Page 4 31...

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Page 53: ...at contributes to the signal Your success in making good light scattering measurements will depend on your ability to prepare clean samples Most often dusty samples limit the reproducibility of the re...

Page 54: ...obtained by atomizing the water through the tip of a narrow gauge needle Clean and flush a syringe and a needle several times to remove coarse particles which will clog a filter prematurely If possib...

Page 55: ...PLE PREPARATION Page 5 3 Figure V 1 Solvent filtration small quantities Syringe Filter Holder Cuvette Figure V 2 Water filtration large quantities Flexible Hose Va ter Supply La rge VoluMe Filter Cuve...

Page 56: ...rements Trace organic material may significantly alter the Rayleigh ratio of the standard used to calibrate the instrument for inten sity measurements Commercial water purification systems are availab...

Page 57: ...SAMPLE PREPARATION Page 5 5 Figure V 3 Water purification Deionize distill filter collecting bottle filter cooling water out condenser boiling flask tap water in t heating mantle overflow W cartridge...

Page 58: ...g liquid frequently Rinse thoroughly in tap water followed by several rinses with filtered water Let dry upside down or cover to prevent dust from collecting inside the cell Sometimes samples adsorb o...

Page 59: ...where the light beam will enter or exit Follow these procedures to clean each cell 1 Soak cells for 30min in conc H2S04 Rinse thor oughly in tap water 2 Soak for lOmin in Solution A Rinse in tap wate...

Page 60: ...gram of boiling chips in the flask Clean the pipette tubing flask and boiling chips with deionized distilled filtered water prior to use Let the steam flow for about 5 minutes before clamping the cel...

Page 61: ...ollow the advice given in specialized literature sources Beware of gels and other supramolecular species which can dominate the light scattering and lead to false conclusions especially at low angles...

Page 62: ...aqueous suspension of this standard will scatter very well and serve as one test of the alignment You will also gain experience using the goniometer and correIator by measuring the particle size of t...

Page 63: ...minutes using short burst perhaps 10 seconds of sonic energy followed by a few seconds of no energy Clean a BI RCI2 or equivalent round glass cell Use the soap and water technique described in this se...

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Page 65: ...ect are listed as references 2 7 at the end of this section It is assumed that the user has a Brookhaven goniometer and correlator Reference will be made to features on these in struments It is furthe...

Page 66: ...s are known for working in the dark Use the closed position as a shutter to protect the photomultiplier tube when not making measure ments Select the 200 u pinhole using the pinhole turret on the dete...

Page 67: ...to the up position clockwise Scattered light is now able to reach the detector Check the count rate as follows Set a duration of 1 second and a sample time of 10p sec Press the START key The count rat...

Page 68: ...rement This is the same command used in the control files You may wish to set the correIator controls manually A lot can be learned by the novice doing it manually the first few times First you need t...

Page 69: ...ch that the last correlation channel stretches out to approximately 1120J sec For example set the number of channels at 10 the ratio spacing at 2 and the first sample time at 2p sec See the correIator...

Page 70: ...er EFF DIAM and POLY This occurs because of either alignment stray light true aggregation or dust Alignment and stray light can be checked by measuring the scattering from a pure liquid as described i...

Page 71: ...concentration or low angle or high laser power where prescaling exponents of 2 3 or 4 are necessary to keep the overflow light from blinking more than occasionally Repeat experiments as a function of...

Page 72: ...smooth curves However the rise above the baseline is 50 or more Since this rise contains the significant information this is the reason the final pinhole should be comparable in area to the coherence...

Page 73: ...ount rate and intensity are used interchangeably even though they are only proportional to each other In the latest versions of Brookhaven correIator control pro grams the count rate in kilocounts sec...

Page 74: ...within the photo multiplier tube chief among them is thermionic emission Cooling the tube below ambient lowers the dark count howev er it produces afterpulsing which is very bad for PCS meas urements...

Page 75: ...e measured count rate For dark count rates it is negligible For the 203OAT with a dead time of 100nsec the correction is 1 at 105 counts sec Above 106 cps the correction is no longer very accurate Cou...

Page 76: ...s The scatterers are much smaller than the wave length of light Molecules of toluene and decalin satisfy this criterion If the intensity from these scatterers is measured as a function of angle then t...

Page 77: ...d by dust Make 5 measurements at each of the following angles 20 30 45 60 90 120 135 150 and 160 At each angle calculate the average after deleting any values that are too high These were probably aff...

Page 78: ...attering situation a 10 dark count of 1 000cps represents 5 Ifyou mistakenly sub tracted only 500cps as the dark count rate then a noticeable 0 90 160 symmetric negative curvature is observed 10 Symme...

Page 79: ...automati cally A least squares routine is included to calculate e If the I sin S plot shows any indication of positive or negative slope even roughly centered on 90 then it is worthwhile applying the...

Page 80: ...until no bright spots is observed coming from the region where the beam enters the cell For the best meas urements you need to reposition cells in the same position that gave the best I sin E results...

Page 81: ...tion Re solvent Excess Rayleigh ratios are used in the determination of molec ular weight from a Zimm plot The Rayleigh ratio is not meas ured directly an intensity is Corrections must be applied to t...

Page 82: ...tector distance r is small as is the case for the BI 200SM the raw intensity measurements must by multiplied by the factor Cn n fiv 2 where llvis the refractive index of the liquid in the vat A simila...

Page 83: ...aller than the uncor rected value Only when there is a significant angular dependence to the scattered light from aqueous solutions is this correction worth considering For a nonaqueous system the cor...

Page 84: ...he calibration liquid glass interface Again the primes were deleted for sim plicity Notice at 90 that the reflection correction is simplified Since the calibration liquid has a refractive index extrem...

Page 85: ...isotropic P and anisotropic f components as follows Vv P 4f and Hv 3f Historically the anisotropic part of the scattering was expressed using depolarization ratios which are defined as follows where t...

Page 86: ...ated from the equa tion in the previous section which relates pv and Pu The absolute errors in Rvare estimated at 2 A very sensi tive but not absolute light scattering instrument was con structed by C...

Page 87: ...e wavelengths It is important to report the value of Rc 900 used for calibra tion If two molecular weight measurements disagree it may be due to different choices of the Rayleigh ratio of the calibrat...

Page 88: ...Toluene Benzene 26 0 X 10 6 0 31 0 26 0 47 0 41 The values in the table above were estimated using the expression at the top ofpage 8 7 The expression was evaluated and plotted as a function ofwavelen...

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