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Vapro 5520 User Manual

Vapor pressure osmometer
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VAPRO
VAPOR PRESSURE OSMOMETER
MODEL 5520
USER'S MANUAL
M2468-4 rev B

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Summary of Contents for Vapro 5520

  • Page 1 ® ® VAPRO VAPOR PRESSURE OSMOMETER MODEL 5520 USER’S MANUAL M2468-4 rev B...
  • Page 2 © 1995-2004 Wescor, Inc. All rights reserved. Printed in the United States of America. Wescor, Vapro, Optimol, Osmocoll and Blow Clean are trademarks of Wescor, Inc. Other trade names used in this manual may be trademarks of their respective owners, used here for information only.

  • Page 3: Table Of Contents

    2.1 Instrument Setup Sequence ......17 2.2 Vapro Accessories ........18 2.3 Setting Up the Osmometer .
  • Page 4 TABLE OF CONTENTS SECTION PREVENTIVE MAINTENANCE 4.1 Preventive Maintenance Overview ....45 4.2 Removing the TC Head ......46 4.3 Cleaning the TC Head .
  • Page 5 TABLE OF CONTENTS APPENDIX E Osmolality Standards ........91 APPENDIX F Serial Data Output .

  • Page 7: Introduction

    You will find it to be a valuable investment and an important partner in the laboratory. The Vapro User’s Manual is your key to efficiently operating this instrument. We recommend that you become thoroughly familiar with the operation procedures and troubleshooting techniques described in this manual.

  • Page 8: Customer Service

    1.2 Customer Service Wescor is ready to help resolve any difficulty with the operation or per- formance of your Vapro osmometer. If you cannot solve a problem using the procedures in this manual, please contact us. Customers within the United States are encouraged to contact us by telephone.

  • Page 9: Vapro System Description

    None of the measurement artifacts that arise in freezing point depression measurements due to elevated viscosity, particulate matter, inhomogeneities, or other physical characteristics of the sample. • Superior reliability because the measurement involves minimal mechanical complexity. NOTE: Vapro displays in Standard International (SI) units: mmol/kg. See Appendix E.

  • Page 10: How The Vapro Works

    S E C T I O N INTRODUCTION 1.4 How the Vapro Works A 10 microliter specimen is aspirated into a micropipettor tip. The specimen is then inoculated into a solute-free paper disc in the sample holder, whereupon the sample holder is pushed into the instrument and the sample chamber is locked.
  • Page 11 Thermocouple and TC Mount TC Head and Connector Thermocouple Head and Sample Chamber Assembly...
  • Page 12 Press Here to Remove Sample Slide / Sample Holder TC Head Access Cover Cover Pipette Guide Display Screen Power SELECT ENTER ENTER Keypad SELECT Keypad Power Indicator...

  • Page 13: Controls And Features

    S E C T I O N INTRODUCTION 1.5 Controls and Features INSTRUMENT FRONT PANEL Display Screen 10 x 7 cm LCD. Displays menu selections, osmolality readings, countdown of measurement time in seconds, operating status, fault conditions, and other information. SELECT Keypad Press to call up menus and to select operation mode.
  • Page 14 Serial Data Port Signal Chime Model and Serial Sample Chamber Lever Power Entry Module Numbers (Shown in the Open Position)
  • Page 15 S E C T I O N INTRODUCTION 1.5 Controls and Features INSTRUMENT RIGHT SIDE Sample Chamber Lever Opens and closes the sample chamber. Closing the sample cham- ber locks the sample holder within the chamber. The chamber should remain closed, except when loading or removing samples. Closing the chamber initiates the measurement cycle or the “Standby”...

  • Page 16: Section

    S E C T I O N INTRODUCTION 1.5 Controls and Features INSTRUMENT REAR PANEL (Continued) Power Entry Module POWER ENTRY MODULE Fuse Door Accepts standard IEC 320 type power cord. Fuse Door Provides access for fuse replacement. See Section 2.8 for instructions.

  • Page 17: Getting Started

    S E C T I O N GETTING STARTED 2.1 Instrument Setup Sequence We recommend that you follow this sequence if you are using this instrument for the first time. Details about these operations are found in the following sections. List 1.

  • Page 18: Vapro Accessories

    S E C T I O N GETTING STARTED 2.2 Vapro Accessories The following accessories and supplies are furnished with the Vapro osmometer: Vapro User’s Manual Micropipettor Micropipettor Disposable Tips Forceps Paper Sample Discs Opti-Mole ® Osmolality Ampule Standards Ampule Organizer...

  • Page 19: Setting Up The Osmometer

    S E C T I O N GETTING STARTED 2.3 Setting Up the Osmometer Carefully unpack the instrument and compare the contents with the packing list to be certain that everything needed for operation is at hand. Place the osmometer on a suitable work sur- face.
  • Page 20 S E C T I O N GETTING STARTED 2.3 Setting Up the Osmometer Turn the osmometer on (I). The POWER indica- tor on the front panel shows green when power is on. The display screen will briefly show the Wescor logo, language and unit selection, and the resident software version.
  • Page 21 S E C T I O N GETTING STARTED 2.3 Setting Up the Osmometer While the instrument compensates for small chang- es that occur over time, moving the instrument to a different area or exposing it to too much air circula- tion will shift the osmometer’s reading and calibra- tion points.

  • Page 22: Micropipettor Information

    S E C T I O N GETTING STARTED 2.4 Micropipettor Information The micropipettor furnished with the Vapro osmometer uses a two- step (aspirate/expel) mechanism that dispenses 10 microliters of liq- uid for osmolality assay. This no-maintenance micropipettor works with a wide range of biological solutions and laboratory reagents.
  • Page 23 2.4 Micropipettor Information Sample Volume Considerations The Vapro osmometer does not demand a high degree of volumet- ric accuracy at the 10 µL sample level. Sample volume variations of ± 10 percent will not noticeably affect the final result. Gross volu-...

  • Page 24: Using Optimol Osmolality Standards

    S E C T I O N GETTING STARTED 2.5 Using Optimol Osmolality Standards Wescor's Opti-Mole ® ampule osmolality standards are accurate enough to satisfy the most stringent quality assurance requirements. Calibration integrity is assured because ampules provide fresh solution for each use.
  • Page 25 Sample directly from the ampule–do not transfer standard solution from ampules to other containers. • Always follow the instructions in Section 3.5 to calibrate your Vapro osmometer, and always verify calibration prior to running any unknowns. See Appendix E for more information.

  • Page 26: Using Osmocoll Hnl Serum Control

    2.6 Using Osmocoll HNL Serum Control Osmocoll ® HNL (SS-039) is a processed, stabilized bovine serum control, which is useful in a quality assurance program for the Vapro osmometer. See Appendix B for more information. For optimum results, always adhere to the following guidelines: •...

  • Page 27: Changing The Voltage Selector

    S E C T I O N GETTING STARTED 2.7 Changing the Voltage Selector The voltage selector is set at the factory. If the volt- age shown does not match your power outlet (see Appendix A for nominal voltage ranges), you must change the voltage selector before plugging the instrument into the outlet.

  • Page 28: Changing Fuses

    S E C T I O N GETTING STARTED 2.8 Changing Fuses To access the main fuses: Turn power off and disconnect the power cord. Use a small screwdriver to open the fuse door. WARNING! For continued protection against fire hazard, only use fuses of the correct type and rating.

  • Page 29: Operating The Vapro Osmometer

    S E C T I O N OPERATING THE VAPRO OSMOMETER 3.1 Operation Overview Menu Selections Two main menus (Mode and Function) are used to select modes and functions of the osmometer. Modes control how the osmometer processes sam- ples and displays results. Use the Mode Menu to...
  • Page 30 S E C T I O N OPERATING THE VAPRO OSMOMETER 3.1 Operation Overview The modes are described below. Normal Mode For routine running of single samples. Does not dis- play any statistical data. This mode is the default setting upon power-up of the instrument.
  • Page 31 S E C T I O N OPERATING THE VAPRO OSMOMETER 3.1 Operation Overview Auto Repeat Mode Checks the repeatability of the osmometer on the same sample. The instrument will automatically run 10 consecutive measurements on the sample, (usu- ally a 1000 mmol/kg Optimol sample) and display the statistical data.
  • Page 32 S E C T I O N OPERATING THE VAPRO OSMOMETER 3.1 Operation Overview FUNCTION MENU To display this menu, press SELECT after a sample has been assayed, and before opening the sample chamber. The osmometer performs the function indi- cated by the arrow when you press ENTER.
  • Page 33 S E C T I O N OPERATING THE VAPRO OSMOMETER 3.1 Operation Overview Delete Result Deletes the last result from the data group. You can delete multiple results using this function. This function can only be used while operating in Average Mode.

  • Page 34: Loading Samples

    OPERATING THE VAPRO OSMOMETER 3.2 Loading Samples When first using the Vapro system, practice the loading procedure using the micropipettor and the 290 mmol/kg standard. Record the value dis- played at the end of the cycle, when the “In Process” display goes out and the chime sounds.
  • Page 35 S E C T I O N OPERATING THE VAPRO OSMOMETER 3.2 Loading Samples Sample Loading Procedure Rotate the sample chamber lever upward and pull the sample slide out from the instrument until it comes to a stop, bringing the sample holder direct- ly under the pipettor guide.
  • Page 36 S E C T I O N OPERATING THE VAPRO OSMOMETER 3.2 Loading Samples With the pipettor tip resting in the notch of the pipettor guide, position the tip about 5 millimeters above the center of the sample disc. Smoothly depress the micropipettor plunger to the stop.
  • Page 37 S E C T I O N OPERATING THE VAPRO OSMOMETER 3.2 Loading Samples Gently push the sample slide into the instru- ment until it stops. (Never close the chamber unless the sample holder is in this position.) Grasping the sample chamber lever between thumb and forefinger, rotate it smoothly to the closed position.
  • Page 38 3.2 Loading Samples The display shows this final reading until the cham- ber is opened and closed once again. NOTE: Vapro reports osmolality measurements in Standard International (SI) units: mmol/kg. CAUTION! During long, uninterrupted measurement periods, occasionally allow the instrument to return to the “standby”...

  • Page 39: Cleaning The Sample Holder

    S E C T I O N OPERATING THE VAPRO OSMOMETER 3.3 Cleaning the Sample Holder To clean the sample holder and prepare for another sample: Smoothly rotate the chamber lever to the open position, then withdraw the sample slide.

  • Page 40: Running The Clean Test

    S E C T I O N OPERATING THE VAPRO OSMOMETER 3.4 Running the Clean Test The Clean Test is a diagnostic feature that compares two consecutive sample assays and uses the differ- ence to determine the contamination level of the thermocouple.

  • Page 41: Calibrating

    S E C T I O N OPERATING THE VAPRO OSMOMETER 3.5 Calibrating For optimum operating accuracy, the instrument must be correctly calibrated according to the instructions in this section. Calibration accuracy depends upon three main factors: • Standard solution accuracy •...
  • Page 42 S E C T I O N OPERATING THE VAPRO OSMOMETER 3.5 Calibrating Initial or Routine Calibration Run a 290 mmol/kg standard. If the osmometer reads within ± 3 mmol/kg of the standard (287 to 293), it is within accept- able calibration limits.

  • Page 43: Standby Or Waiting Periods

    If the chamber is left open for longer than 2 minutes, a warning chime sounds. When in the standby mode, the Vapro osmometer is not idle. It continuously monitors its internal operat- ing temperature and compensates for changing ambient temperatures that would otherwise result in calibration changes.

  • Page 44: Serial Data Output

    S E C T I O N OPERATING THE VAPRO OSMOMETER 3.7 Serial Data Output The 5520 serial port uses a DB9 connector on the instrument back panel. This port is for asynchronous serial communication with a printer or computer. It uses standard non-return-to-zero (NRZ) format at RS-232 voltage levels.

  • Page 45: Preventive Maintenance

    4.1 Preventive Maintenance Overview Cleaning the thermocouple (TC) head is the only routine mainte- nance required by the Vapro osmometer. This section will guide you through the necessary steps of removing, cleaning and reinstalling the TC head. Also included are methods for identifying and resolv- ing more difficult thermocouple contamination situations.

  • Page 46: Removing The Tc Head

    S E C T I O N PREVENTIVE MAINTENANCE 4.2 Removing the TC Head Turn the power switch off. Rotate the sample chamber lever to the open position. Remove the TC head access cover from the top of the osmometer by pressing down on the right hand edge, then lifting the raised edge up and away.
  • Page 47 S E C T I O N PREVENTIVE MAINTENANCE 4.2 Removing the TC Head Using the 9/64 inch hex driver, completely loosen (but do not remove from the TC head) the attachment screws. Grasp the top of the TC head (with the loose attachment screws still in the head) and lift it straight up and out of the instrument.

  • Page 48: Cleaning The Tc Head

    π S E C T I O N PREVENTIVE MAINTENANCE 4.3 Cleaning the TC Head Materials needed to clean the TC head: Wescor Cleaning Solution, (SS-003) Thermocouple Cleaning Solution with Anionic Detergent (SS-223) Purified Water Liquid Dropper Blow Clean Liquefied Propellant or Equivalent. (Pressure limited to 20 psig.) NOTE: To remove significant contamination, use both the...
  • Page 49 S E C T I O N PREVENTIVE MAINTENANCE 4.3 Cleaning the TC Head Hold the TC head over the waste container. Quickly pull the TC head straight down and away from the droplet of liquid, allowing liquid to fall into the waste container directly below. Immediately apply rinse water before evaporation can occur.
  • Page 50 S E C T I O N PREVENTIVE MAINTENANCE 4.3 Cleaning the TC Head Repeat this procedure at least ten times, using enough water to cover the central depression and thermocouple. CAUTION! Shaking or tipping the can of Blow Clean will severely contaminate the thermocouple.

  • Page 51: Reinstalling The Tc Head

    S E C T I O N PREVENTIVE MAINTENANCE 4.4 Reinstalling the TC Head Verify that the sample chamber lever is in the open position. Replace the TC head. CAUTION! The instrument will not hold calibration if the chamber screws are loose. Power SELECT ENTER...
  • Page 52 S E C T I O N PREVENTIVE MAINTENANCE 4.4 Reinstalling the TC Head Replace the access cover. Close the sample chamber. Turn on the power. Allow the instrument to complete the initial- ization sequence and reach thermal equilibrium (see Section 4.5) before attempting to calibrate the osmometer.

  • Page 53: Equilibration After Cleaning

    S E C T I O N PREVENTIVE MAINTENANCE 4.5 Equilibration After Cleaning Cleaning the thermocouple mount changes the thermal equilibrium of the instrument and causes a temporary shift in calibration after the TC head is reinstalled. After reinstalling the thermocouple head, allow the instrument to regain thermal equilibrium.

  • Page 54: Severe Or Stubborn Contamination

    S E C T I O N PREVENTIVE MAINTENANCE 4.6 Severe or Stubborn Contamination If the Clean Test indicates residual contamination in spite of a clean appearance: Repeat the cleaning procedure. Calibrate the instrument using the 290, 1000, and 100 mmol/kg standards.

  • Page 55: Section

    S E C T I O N PREVENTIVE MAINTENANCE 4.6 Severe or Stubborn Contamination Removing Difficult Contamination Many contaminants can be detected and removed under microscopic examination. If cleaning fails to produce an acceptable clean test, examine the ther- mocouple head under a microscope at 30X to 60X power.
  • Page 56 S E C T I O N PREVENTIVE MAINTENANCE 4.6 Severe or Stubborn Contamination To clean dark or corroded copper connection points: Apply a droplet of concentrated ammonium hydroxide (NH 4 OH, 28 to 30%) or household lime remover to the TC mount. Soaking with this solution for a few minutes will reduce oxida- tion and restore the bright copper color.

  • Page 57: Solving Problems

    5.1 Troubleshooting This section describes problems you might encounter in using the Vapro osmometer, with suggested solutions. The first part is a flow chart to help you identify problems by symptom. Beginning with the apparent symptom, trace through the flow chart to identify possible causes and solutions for the difficulty.
  • Page 58 S E C T I O N SOLVING PROBLEMS 5.1 Troubleshooting START Large Shift in Poor Linearity in No Display Calibration Low Range Allow Is Power Is Temperature Temperature to Indicator Lit? Stable? Stabilize Check if Power Are Calibration Obtain Fresh Switch is On Standards Standards...
  • Page 59 S E C T I O N SOLVING PROBLEMS 5.1 Troubleshooting MESSAGE MESSAGE Abnormal Erratic Reading "ERROR Check "Calibration Error" Display Thermocouple" Run an Auto Restart Check TC Verify Calibration Repeat using Instrument Connector Standard 1000 Clean Thermocouple Broken or Check for Loose Is S.D.
  • Page 60 S E C T I O N SOLVING PROBLEMS 5.1 Troubleshooting The following is a detailed presentation of material covered in the Troubleshooting Flowchart. This material is indexed to further information found throughout the manual. Problem Solution Display is blank. Check to see if power indicator is lit.
  • Page 61 S E C T I O N SOLVING PROBLEMS 5.1 Troubleshooting Problem Solution There is a large Check the freshness of the calibration standards shift in calibration. and replace if needed. See Section 4. Calibrate the insturment and then run the Clean Test. If the contamination level is greater than 10, clean the thermocouple.
  • Page 62 S E C T I O N SOLVING PROBLEMS 5.1 Troubleshooting Problem (Continued) Solution There is poor linearity If, after taking the above steps, the error in the low range (below message again appears after running the 200 mmol/kg). Clean Test, check the TC mount for gross (visible) contamination.
  • Page 63 S E C T I O N SOLVING PROBLEMS 5.1 Troubleshooting Problem Solution Calibration deteriorates Check for deformed or broken thermocouple. after cleaning the TC mount. Abnormal display, or sample Reset instrument by turning the power off for at least 15 reading on an empty chamber, seconds, then turn power back on.
  • Page 64 S E C T I O N SOLVING PROBLEMS 5.1 Troubleshooting Problem Solution The following error Be sure that you are using the correct calibration message appears on standard. the screen: Check the TC head connector for faulty connection. Clean the thermocouple. Check for loose TC head screws.

  • Page 65: Common Tc Head Problems

    S E C T I O N SOLVING PROBLEMS 5.2 Common TC Head Problems Many years of field experience have shown that the majority of problems encountered with the osmometer are with the thermocou- ple sensor. It is suspended from the thermocouple mount, which forms the upper half of the sample chamber.
  • Page 66 S E C T I O N SOLVING PROBLEMS 5.2 Common TC Head Problems Problems can often be solved by inspecting and cleaning the TC head. Follow the instructions in Section 4 to remove the TC head. NOTE: To improve temperature stability inside the osmometer, leave the access cover in place while the TC head is out of the instrument.
  • Page 67 S E C T I O N SOLVING PROBLEMS 5.2 Common TC Head Problems NOTE: Always switch power off before connecting or disconnecting the TC head. If the connector is damaged, electrical connection may be compro- mised or fail altogether. A failed connection produces an ERROR message on the display, as with a broken thermocouple.

  • Page 68: External Factors Affecting Precision

    S E C T I O N SOLVING PROBLEMS 5.3 External Factors Affecting Precision Problems with instrument precision have a number of possible sources. Often, poor reproducibility is caused by external factors that are entirely independent of the instrument itself. The following are some of these factors: •...

  • Page 69: Deformed Or Broken Thermocouple

    S E C T I O N SOLVING PROBLEMS 5.4 Deformed or Broken Thermocouple The thermocouple is well protected while the TC head is in the instrument. Cleaning procedures detailed in this manual should not harm the thermo- couple, but it can be deformed or broken if contact- ed by any object while it is out of the instrument.
  • Page 70 S E C T I O N SOLVING PROBLEMS 5.4 Deformed or Broken Thermocouple Make a tool by cutting a thin sliver or wedge from a sheet of ordinary paper. Work the pointed end of the paper sliver under the thermocouple wire. Use the paper sliver to lift and reshape the thermocouple.

  • Page 71: Instrument Specifications

    A P P E N D I X Instrument Specifications Sample Volume 10 µL nominal (Larger samples or samples as small as 2 µL can be measured reliably with special procedures) Measurement Range Typically 0 to 3200 mmol/kg* @ 25 °C ambient Measurement Time 80 seconds Resolution...

  • Page 73: Accessories, Supplies, And Replacement Parts

    Accessories, Supplies, and Replacement Parts ACCESSORIES AC-037 Micropipettor, 10 microliter AC-061 Ampule Organizer AC-066 Thermocouple Head Assembly, model 5520 0 to 3200 mmol/kg AC-067 Thermocouple Head Assembly, model 5520 above 3200 mmol/kg AC-011 Hex Driver, 9/64 (screwdriver handle) AC-036 Forceps, 5-inch, stainless steel...
  • Page 74 TC Head Extended Range (above 3200 mmol/kg) FACTORY SERVICE FS-255 Thermocouple Clean and Check Service MANUALS and INSTRUCTIONAL MATERIALS M2468 5520 Vapro Osmometer User's Manual M2469 5520 Vapro Osmometer Service Manual V-1003 Thermocouple Cleaning Video, VHS Format (specify NTSC, PAL, or SECAM)

  • Page 75: Theory Of Operation

    A P P E N D I X Theory of Operation Osmolality is an expression of the total concentration of dissolved particles in a solution without regard for particle size, density, con- figuration, or electrical charge. Indirect means for the measurement of osmolality are afforded by the fact that the addition of solute par- ticles to a solvent changes the free energy of the solvent molecules.
  • Page 76 In the Vapro vapor pressure osmometer, a 10 microliter sample of the solution to be tested is pipetted onto a small, solute-free paper disc which is then inserted into a sample chamber and sealed.
  • Page 77 A P P E N D I X Theory of Operation PROGRAM STEP 2, COOLING An electrical current is passed through the thermocouple, cooling it by means of the Peltier Effect to a temperature below the dew point. Water condenses from the air in the chamber to form microscopic droplets upon the surface of the thermocouple.
  • Page 78 A P P E N D I X Theory of Operation THERMOCOUPLE TEMPERATURE VS. TIME (with 290 mmol/kg sample) AMBIENT TEMPERATURE DEW POINT TEMPERATURE ∆T WET BULB TEMPERATURE DEPRESSION DEW POINT TEMPERATURE PRE-CONVERGENCE TEMPERATURE Typical curve for closed chamber EQUILIBRATION COOLING CONVERGENCE READOUT (SAMPLE-HOLD)
  • Page 79 A P P E N D I X Theory of Operation THERMOCOUPLE TEMPERATURE VERSUS OSMOLALITY The graph on the left is a plot of thermocouple temperature versus time as the instrument cycles through the program, beginning with chamber closure (time = 0). The graph depicts the excursion of thermocouple temperature that typically occurs during each of the program steps outlined above.

  • Page 81: Special Application Notes

    Special Application Notes Clinical and General Research The Vapro osmometer has unique advantages in many aspects of clini- cal chemistry due to its very small sample requirement. This is particu- larly true in pediatric practice. For example, the amount of sample col-...
  • Page 82 A P P E N D I X Special Application Notes PROCEDURE FOR VERY SMALL SAMPLES You can measure samples with very low volumes (under 4 µL) using the following procedures. Sample discs must be hand made from high-grade filter paper (Whatman #1 or equivalent) using a high-precision 1/8 inch diame- ter paper punch to produce discs with a very clean edge.
  • Page 83 A P P E N D I X Special Application Notes SPECIAL LOW VOLUME PROCEDURE: Preparing Paper Discs Use a (Mieth or equivalent) 1/8 inch diameter punch to create a supply of paper discs. Punch only one thickness of paper stock at a time, to prevent paper discs from sticking together.
  • Page 84 A P P E N D I X Special Application Notes Instructions Prior to running the 2 µL samples, calibrate the instrument using 10 µL samples at the 290, 1000, and 100 mmol/kg calibration set points. Insert the 2 µL sample holder and calibrate on the 290 mmol/kg standard.
  • Page 85 A P P E N D I X Special Application Notes MEASURING LARGE SAMPLES Measuring large samples requires consideration of the nature and size of the sample. You should experiment with these procedures to find the best approach for your particular application. Samples such as leaf discs, tissues, and other solids often require considerable time to reach equilibrium.
  • Page 86 A P P E N D I X Special Application Notes Instructions For best precision, use the smallest holder that can accommo- date the sample volume without danger of contaminating the thermocouple. CAUTION! Never load any sample that extends above the lip of the sample holder. Solid sample material extending above the lip of the sample holder can severely contaminate or even break the thermocouple.
  • Page 87 A P P E N D I X Special Application Notes Press ENTER to make a measurement. Osmolality is dis- played when the measurement is complete. For repeat measurements, leave the chamber closed and press ENTER. Readings should be lower with each successive assay until equilibrium is reached.
  • Page 88 A P P E N D I X Special Application Notes SAMPLING VISCOUS AND/OR NONHOMOGENEOUS SPECIMENS The broad range of specimen materials amenable to testing in the vapor pressure osmometer may require you to adapt your sampling technique to suit the physical characteristics of unusual samples. Using the micropipettor will assure the application of uniform vol- umes of both test specimen and calibrating solutions, but if the vis- cosity of the sample is extremely high, a positive-displacement...
  • Page 89 A P P E N D I X Special Application Notes OSMOMETRY WITH MULTI-SOLVENT SOLUTIONS Biological solutions, in general, are aqueous in nature. Most speci- mens submitted to the clinical laboratory for testing, both pathologic and normal, will exhibit characteristic properties that are essentially attributable to the cardinal properties of water, as modified by the dissolved solute particles.
  • Page 90 A P P E N D I X Special Application Notes You must be aware of this phenomenon if you are to correctly inter- pret results. By way of illustration, the table below depicts the results of solution osmolality measurements made by both vapor pressure and freezing point osmometers for varying amounts of ethanol in human blood serum.

  • Page 91: Osmolality Standards

    A P P E N D I X Osmolality Standards STANDARD INTERNATIONAL (Sl) UNITS OF OSMOLALITY Osmolality, by definition, is an expression of the total number of solute particles dissolved in one kilogram of solvent without regard for particle size, density, configuration, or electrical charge. Traditionally, osmolality has been expressed as milliosmols per kilo- gram, with various abbreviations such as mOs/kg, mOsm/kg, and mOsmol/kg.
  • Page 92 A P P E N D I X Osmolality Standards With complex solutions, such as biological fluids, analytical vari- ables are universally expressed as the concentration of specific ions and of undissociated solute particles. It follows that a molal solution of NaCI can be analytically expressed as a combination of a molal solution of sodium ions and a molal solution of chloride ions.

  • Page 93: Serial Data Output

    It uses standard non-return-to-zero (NRZ) format at RS-232 voltage levels. The 5520 checks to see if the RTS (pin 7) is active. When a sample is assayed while a device is connected to the 5520's RS-232 port, the display status line will show: To send data to the external device, press ENTER.
  • Page 94 A P P E N D I X Serial Data Output Pin Diagram: Pin # Mnemonic Description Data Carrier Detect (output) Pin 1 Receive Data (output) Transmit Data (input) No Connection Signal Ground (passive) Data Set Ready (output) Request to Send (input) Clear to Send (output)

  • Page 95: Appendix G Setup Menu

    A P P E N D I X Setup Menu The Setup Menu allows you to select available lan- guages: English, French, or German and available measurement units: mmol/kg or kilopascals at 25 °C (= -2.5 x mmol/kg). It also allows you to run a Self Test on the instrument to check basic input and out- put functions.
  • Page 96 = NON FLOW CONTROL = RTS?CTS BAUD RATE = 1200 bps Connect the data cable from the Vapro to the printer. The READY prompt and all measurement results will now be printed as they are dis- played on the Vapro display.

  • Page 97: Index

    Index Carry-over Error 88 Chime Accessories 73, 74 signal 14, 37 Accuracy warning 20, 38 of standards 24, 25, 92 Claussius-Clapeyron Equation 79 of reported osmolality 25 Clean Test 32, 34, 39, 40, 45, 50, 52, 54, 58, Ambient Temperature 10, 43, 60, 82 Ammonium Hydroxide 48, 55, 56 Colligative properties 9, 75, 89 Ampule...
  • Page 98 Index Function Calibrate 32, 33, 41, 42 Language Clean Test 32, 40 changing 95 Delete Result 33 display 95 Menu 29, 32, 42 Linearity Fuse(s) 16 in low range 61, 62, 66 changing 28 Line Voltage 71 door 16, 28 specifications, 28, 71 Malfunction (see Electronic) Measurement...
  • Page 99 Index Mode(s) Auto Repeat 31 Paper punch 82 Average 30 Paper Sample Disc(s) 10, 18, 35, 36, 39, 75 Menu 29 for special applications 82, 83, 84, 86 changing 29 measuring without 88 selecting 29 Pipette Normal 30 guide 12, 13, 36 Process Delay 31 tip 10, 35 "Standby"...
  • Page 100 Index Special Applications 81-90 Clinical and General Research 81 Sample(s) Specimen complex 31, 81, 89 feces 81 holder 10, 12, 35, 36 gastrointestinal aspirate 81 cleaning 39, 45, 84 physical state 9 special purpose 81, 82 removing 38 leaf disc, 85 sputum 81 loading 34, 35, 82, 84 sweat 81...
  • Page 101 Index Thermocouple (TC) head cleaning 48-50, 55, 66 cleaning supplies 18, 48 connector 15, 46, 51, 65-67 inspecting 66 oxidation 56 removing 45, 46, 47 reinstalling, 51, 67 screws 59, 61, 62, 64, 65 hygrometer 10, 76 hygrometry 76 mount 10, 65, 70 sensor 65 temperature graph 78, 79 Tissue Paper 82...

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