2005-02-11 17:27 Page i SWEAT• CHEK™ SWEAT CONDUCTIVITY ANALYZER op y Model 3120 Instruction/Service Manual M2672-2A C M2672-2A i
M2672-2A 2005-02-11 17:27 Page ii © 2005 Wescor, Inc. All rights reserved. Printed in the United States of America. Wescor, Macroduct, Sweat-Chek, Webster Sweat Inducer and Calibrator are trademarks of Wescor, Inc. Other trade names used in this manual may be trademarks of their respective owners, used here for information only. U.S. Patent Numbers 4,383,529; 4,542,751. U.K. Patent Number 2,116,850. German Patent (DBP) 33 09 273. All information in this manual is subject to change without prior notice.
M2672-2A 2005-02-11 17:27 Page iii section 1 INTRODUCTION 1.1 1.2 1.3 1.4 Instrument Description . . . Customer Service . . . . . Controls and Connections . Important User Information. . . . . . . . . . . . . 3 4 5 6 . . . . . . . . . . . . . . . . . . . . . . . . . 9 11 13 14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M2672-2A iv 2005-02-11 17:27 Page iv
M2672-2A 2005-02-11 17:27 Page 1 S E C T I O N 1 INTRODUCTION 1
M2672-2A 2005-02-11 S E C T I O N 17:28 Page 2 1 INTRODUCTION 1.
M2672-2A 2005-02-11 17:28 Page 3 S E C T I O N 1 INTRODUCTION 1.1 Instrument Description The 3120 SWEAT•CHEK Sweat Conductivity Analyzer provides simple and economical sweat analysis for the laboratory diagnosis of cystic fibrosis. Designed specifically for use with the Wescor Macroduct® Sweat Collector, it can measure the electrolyte concentration of a sweat specimen as small as 6 to 10 microliters.
M2672-2A 2005-02-11 S E C T I O N 17:28 Page 4 1 INTRODUCTION 1.2 Customer Service Wescor is ready to help you resolve any problems with your SWEAT•CHEK Analyzer. If you cannot solve a problem using the procedures in this manual please contact us. Customers within the United States and Canada are encouraged to contact us by telephone. Outside the U.S., many of our authorized dealers offer complete customer service and support.
M2672-2A 2005-02-11 17:28 Page 5 S E C T I O N 1 INTRODUCTION 1.3 Controls and Connections DIGITAL DISPLAY INSTRUMENT FRONT INLET/OUTLET NIPPLES WAIT INDICATOR READY INDICATOR CONDUCTIVITY CELL POWER INDICATOR INSTRUMENT REAR CALIBRATING TOOL MODEL AND SERIAL NUMBER POWER CORD RECEPTACLE POWER SWITCH CALIBRATION PORT POWER ENTRY MODULE The power switch is located on the back of the instrument as part of the Power Entry Module.
M2672-2A 2005-02-11 S E C T I O N 17:28 Page 6 1 INTRODUCTION 1.4 Important User Information SPECIFICATION OF SAFE USE: Using this instrument in a manner not specified by Wescor may impair the safety protection designed into the equipment and may lead to injury. SAFE USE ENVIRONMENT: This device has been designed for indoor use only, between 5 and 40 °C, maximum relative humidity 80%, at up to 31 °C. For use at altitudes up to 2000 meters. FUSES: All fuses in this equipment are time-lag (Type T).
M2672-2A 2005-02-11 17:28 Page 7 S E C T I O N 2 OPERATING SWEAT•CHEK 7
M2672-2A 8 2005-02-11 17:28 Page 8
M2672-2A 2005-02-11 17:28 Page 9 S E C T I O N 2 OPERATING SWEAT•CHEK 2.1 Instrument Preparation 1 The power switch is located on the back panel in the power entry module. Make certain the switch is OFF (0). 2 Plug the female end of the power cord into the power entry module. Note the voltage indicator window. If the voltage does not match the voltage of your power outlet, refer to Appendix C before proceeding.
M2672-2A 2005-02-11 S E C T I O N 17:28 Page 10 2 OPERATING SWEAT•CHEK 2.1 Instrument Preparation 10 5 Attach a length of clean microbore tubing (SS044) to serve as the outlet tube to one of the stainless steel nipples. While either nipple can be used, we suggest that the right hand nipple be used as the outlet. 6 Check calibration before introducing specimen, (see Section 2.4). After calibration (if needed), clean and dry the cell before proceeding with analysis, (see Section 2.3).
M2672-2A 2005-02-11 17:28 Page 11 S E C T I O N 2 OPERATING SWEAT•CHEK 2.2 Sweat Analysis The Macroduct Sweat Collection System manual provides complete instructions for sweat collection. These should be followed rigorously. Normally, the sweat specimen is introduced directly into the conductivity cell from the Macroduct collection tube. A typical Macroduct sweat collection produces many times the sweat volume needed for analysis.
M2672-2A 2005-02-11 S E C T I O N 17:29 Page 12 2 OPERATING SWEAT•CHEK 2.2 Sweat Analysis CAUTION! Push the tubing STRAIGHT ON to the stainless steel nipples without bending them. Repeated bending will eventually cause the nipple to fracture, requiring replacement of the conductivity cell. the specimen into the cell by gently moving 2 Transfer the syringe plunger into its barrel.
M2672-2A 2005-02-11 17:29 Page 13 S E C T I O N 2 OPERATING SWEAT•CHEK 2.3 Cleaning the Conductivity Cell 1 After testing each specimen, rinse the conductivity cell with at least one full take-up tube of deionized water. 2 When all residual salt has been flushed from the cell, the reading on the display reads “000” (with pure water in the cell). 3 Remove water by using the syringe to push air through the cell.
M2672-2A 2005-02-11 S E C T I O N 17:29 Page 14 2 OPERATING SWEAT•CHEK 2.4 System Operating Checks SWEAT•CHEK is factory-calibrated and under normal conditions should not require further adjustment. IF THE CELL IS CLEAN AND FREE OF RESIDUAL SALT OR WATER, calibration of the instrument can be checked using a freshly opened NaCl standard solution such as that initially supplied with the instrument.
M2672-2A 2005-02-11 17:29 Page 15 S E C T I O N 3 INTERPRETATION OF RESULTS 15
M2672-2A 16 2005-02-11 17:29 Page 16
M2672-2A 2005-02-11 17:29 Page 17 S E C T I O N 3 INTERPRETATION OF RESULTS 3.1 Background Children afflicted with cystic fibrosis (CF) clearly show elevated electrolyte concentrations in their sweat, compared with the sweat of children unaffected by this disease.1,2 With increasing age, however, the difference between normal and abnormal sweat electrolyte levels becomes less distinct; thus, the borderline and low abnormal results commonly encountered in adults are not indicative of disease.
M2672-2A 2005-02-11 S E C T I O N 17:29 Page 18 3 INTERPRETATION OF RESULTS 3.1 Background Licht,10 Gibson,11 Phillips,12 Shwachman,13 and others extensively investigated conductivity as an alternative method of sweat analysis. They concluded that conductivity can be a reliable laboratory indicator to either rule out or confirm the clinical diagnosis of cystic fibrosis. See Section 3.4 for more information on the status of conductivity.
M2672-2A 2005-02-11 17:29 Page 19 S E C T I O N 3 INTERPRETATION OF RESULTS 3.2 Units of Measurement and Clinical Ranges In addition to sodium and chloride ions, sweat also contains significant concentrations of potassium, bicarbonate, and lactate ions. This poses a problem when selecting a reference or calibration solution, but sodium chloride solutions serve well if allowance is made for the other electrolytes.
M2672-2A 2005-02-11 S E C T I O N 17:29 Page 20 3 INTERPRETATION OF RESULTS 3.2 Units of Measurement and Clinical Ranges Among the patient populations mentioned above, data on chloride ion assay and sodium plus potassium ion assay, determined simultaneously with the conductivity data, enables linear regression analysis: Chloride Ion Concentration VS. Sweat Conductivity n = 514 r = 0.974 Cl¯ = 0.96 (C) -15.21 Sodium + Potassium Ion Concentration VS. Sweat Conductivity n = 514 r = 0.
M2672-2A 2005-02-11 17:29 Page 21 S E C T I O N 3 INTERPRETATION OF RESULTS 3.3 Conductivity and the CAP Survey Program The readout in mmol/L (equivalent NaCl) means that the sweat sample has a conductivity equivalent to that of a NaCl solution of the displayed mmol/L concentration (at the same temperature). This reading DOES NOT represent the actual concentration of either sodium or chloride in the sweat.
M2672-2A 2005-02-11 S E C T I O N 17:29 Page 22 3 INTERPRETATION OF RESULTS 3.3 Conductivity and the CAP Survey Program For example, a laboratory finding a conductivity result of 70 mmol/L (equiv. NaCl) would judge this as an equivocal result in terms of the recommended diagnostic ranges for conductivity based on clinical trials. If it had been properly presented to the conductivity section of the Survey, it would be correctly judged by its peer group (conductivity users) as equivocal.
M2672-2A 2005-02-11 17:29 Page 23 S E C T I O N 3 INTERPRETATION OF RESULTS 3.4 Conductivity in the Diagnostic Analysis of Sweat Recently much confusion has arisen in laboratory departments after the publication of the recommendations of the National Committee for Clinical Laboratory Standards, (Sweat Testing Guideline C34-A) that have been adopted by the Cystic Fibrosis Foundation of America.
M2672-2A 2005-02-11 S E C T I O N 17:29 Page 24 3 INTERPRETATION OF RESULTS 3.4 Conductivity in the Diagnostic Analysis of Sweat Further, a comparative statistical analysis of the extensive chloride data of Shwachman,17 the Macroduct trial results of various electrolytes versus conductivity by Hammond, and osmolality results from Webster clearly shows that conductivity, chloride, and osmolality are equivalent in their ability to discriminate between non-CF and CF groups.
M2672-2A 2005-02-11 17:29 Page 25 S E C T I O N 3 INTERPRETATION OF RESULTS 3.5 Reportable Range and its Justification The following information is provided to help you meet regulatory and quality requirements: 1. Reportable Range The reportable range with Sweat-Chek conductivity measurement is 0 to 150 mmol/L, defined as the range of values that have been established as providing acceptably accurate laboratory results for the intended clinical use. 2.
M2672-2A 2005-02-11 S E C T I O N 17:29 Page 26 3 INTERPRETATION OF RESULTS 3.6 References References 1. di Sant’ Agnese, P.A., Darling, R.C., Perera, G.A., Shea, E., Sweat electrolyte disturbances associated with childhood pancreatic disease. Am J Med, 1953;777-784. 2. Clarke, J.T., Ellian, E., Shwachman, H., Components of sweat. Am J Dis Child 1961;101:490. 3. Gibson, L.E., The decline of the sweat test. Clin Pediatr 1973;12:450. 4. Rosenstein, B.J., Langbaum, T.S., Gordes, E., Brusilow, S.W.
M2672-2A 2005-02-11 17:29 Page 27 S E C T I O N 4 TROUBLESHOOTING AND SERVICE 27
M2672-2A 28 2005-02-11 17:29 Page 28
M2672-2A 2005-02-11 17:29 Page 29 S E C T I O N 4 TROUBLESHOOTING AND SERVICE 4.1 Troubleshooting and Service Overview The SWEAT•CHEK analyzer is designed to be simple to operate and easy to maintain. The following troubleshooting chart provides suggestions to help you quickly solve routine problems that might be encountered using the SWEAT•CHEK Analyzer. These solutions are indexed to additional information found in this section.
M2672-2A 2005-02-11 S E C T I O N 17:29 Page 30 4 TROUBLESHOOTING AND SERVICE 4.2 Instrument Calibration The instrument must be calibrated if the conductivity cell has been replaced or if you determine that recalibration is needed (see System Operating Checks, Section 2.4). Two common factors can influence the reading, so before performing recalibration, be sure to check the following: A. RESIDUAL SALT OR WATER IN THE CONDUCTIVITY CELL.
M2672-2A 2005-02-11 17:29 Page 31 S E C T I O N 4 TROUBLESHOOTING AND SERVICE 4.2 Instrument Calibration If you have eliminated the possibility of error from other sources, and recalibration is indicated, the procedure is as follows: CALIBRATOR SOLUTION INTO THE CON1 INJECT DUCTIVITY CELL. a. Connect a new tube (Wescor catalog number SS-044) to the outlet (right) nipple of the cell. b.
M2672-2A 2005-02-11 S E C T I O N 17:29 Page 32 4 TROUBLESHOOTING AND SERVICE 4.2 Instrument Calibration CALIBRATION 2 ADJUST Insert the small end of the calibration tool into the small calibration port on the left side of the analyzer. With the tool seated in the small slot in the bottom of the port, observe the display while rotating the tool in either direction until the display agrees with the assayed molarity of the Calibrator solution.
M2672-2A 2005-02-11 17:29 Page 33 S E C T I O N 4 TROUBLESHOOTING AND SERVICE 4.3 Replacing the Conductivity Cell If one of the stainless steel nipples of the conductivity cell breaks, you must replace the cell assembly (see Appendix C for details). Use the following procedure: 1 Switch the instrument off and disconnect line power. 2 Remove the cell cover. a. Remove the small Phillips-head screws located in the recess of the cover on each side of the nipples. b.
M2672-2A 2005-02-11 S E C T I O N 17:29 Page 34 4 TROUBLESHOOTING AND SERVICE 4.3 Replacing the Conductivity Cell 4 5 6 34 INSTALL THE NEW CONDUCTIVITY CELL Make certain that the nipples of the new cell assembly align precisely with the holes in the cover before installing the cell in the instrument. Hold the circuit board with needle-nose pliers. Then, position the cell so that its connector engages properly with the pins protruding from the circuit board connector inside the instrument.
M2672-2A 2005-02-11 17:29 Page 35 A P P E N D I X A INSTRUMENT SPECIFICATIONS 35
M2672-2A 36 2005-02-11 17:29 Page 36
M2672-2A 2005-02-11 17:29 Page 37 APPENDIX A Instrument Specifications Minimum Sample Volume Accuracy Useful Range Critical Range/Linear Error Sample Stabilization Time Cell Warm-up Time Readout Calibration Reference Cell Set Temperature Line Voltage Options* Power Fuse Dimensions Weight 6-10 microliters 2 mmol/L (1 S.D.
M2672-2A 38 2005-02-11 17:29 Page 38
M2672-2A 2005-02-11 17:29 Page 39 A P P E N D I X B ACCESSORIES, SUPPLIES, AND REPLACEMENT PARTS 39
M2672-2A 40 2005-02-11 17:29 Page 40
M2672-2A 2005-02-11 17:29 Page 41 APPENDIX B Accessories, Supplies, and Replacement Parts Contact Wescor for a complete list of replacement parts.
M2672-2A 42 2005-02-11 17:29 Page 42
M2672-2A 2005-02-11 17:29 Page 43 A P P E N D I X C CHANGING THE VOLTAGE SELECTOR 43
M2672-2A 44 2005-02-11 17:29 Page 44
M2672-2A 2005-02-11 17:29 Page 45 APPENDIX C Changing the Voltage Selector The voltage setting is designated at the factory before shipping. If the voltage shown does not match your power outlet, you must change the voltage selector before plugging the instrument into the outlet. To change the voltage selector: 1 Switch the power off and remove the power cord from the power entry module. 2 Use a screwdriver to open the fuse access door from the right end of the power entry module.
M2672-2A 46 2005-02-11 17:29 Page 46
M2672-2A 2005-02-11 17:29 Page 47 INDEX 47
M2672-2A 48 2005-02-11 17:29 Page 48
M2672-2A 2005-02-11 17:29 Page 49 INDEX A Abnormal Results 19 Air bubbles 11, 12 Ampule organizer 41 Anion Assay 17 Control values 17 Customer service 4, 29 Cystic fibrosis 3, 14, 17, 19 clinical diagnosis of 3, 17, 19 clinical data 19, 20 laboratory confirmation of 17 B Bicarbonate ions in sweat 19 Borderline (see also Equivocal) Results 19, 25 D Diagnostic result 14 Digital display 3, 5, 9, 11, 13, 23, 25, 29 C Calibration 10, 14, 30-32, 34 port 5, 32 reference 30 solution 11, 19, 30-32 tool 5, 32
M2672-2A 2005-02-11 17:29 Page 50 INDEX Measurement(s) 12, 17 artifact 13 errors 11, 13 repeating 12 Microbore tubing 3, 10, 13, 19 N Negative error 14 Nipples broken 14, 23, 33 inlet 3, 5, 10,11, 12 loose 23 outlet 3, 5, 10, 11, 12 Normal Results 19, 25 O Operating temperature 9 Osmolality controls 17 P Positive error 14 Positive results 22, 25 Potassium ion assay 20 Potassium Ions in Sweat 19, Power cord 9 cord receptacle 5 entry module 5, 9, 33 indicator 5 requirements 29 spikes 9 surges 9 switch 5,
