3100 SWEAT CHEK Instruction and Service Manual M2853-3

Contents SECTION 1 INTRODUCTION Instrwnent Description... 1-1 Specifications for Model 3100 SweatoChek™ • • • • • • • • • • • • • • • • • • • • •• • • • • • • •• 1-2 Accessories and Supplies... 1-2

SECTION 2 OPERATION Instrwnent Preparation ... Sweat Collection and Preparation of the Specimen Previously Collected Sweat or Standard Solution Measurement ... ;... Cleaning the Conductivity Cell... System Operating Checks...

2-1 2-2 2-3 2-3 2-4 2-4

SECTION 3 INTERPRETATION OF RESULTS Background Units of Measure and Clinical Ranges References

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3-1 3-2 3-3

SECTION 4 SERVICE InstrUmentCalibration Replace the Conductivity Cell Factory Assistance

4-1 4-3 4-4

SECTION 1

INTRODUCTION Instrument Description The 3100 SweatoChek™ Sweat Conductivity Analyzer provides a simple and economical means of sweat analysis for laboratory diagnosis of cystic fibrosis. The instrument is designed specifically for use with the Wescor® Macroduct® Sweat Collection System. It is capable ofmeasuring the conductivity of a sweat specimen of 6 to lO microliters.

FIGURE 1-1

DIGITAL DISPLAY

The Analyzer features a flow-through conductivity cell that operates at a precisely controlled temperature for improved stability and accuracy. In keeping with established practice, the readout on the digital display is calibrated in mmol/L, representing the molar concentration of a NaC1 solution equivalent in conductivity to that of the sample.

STATUS INDICATOR POWER INDICATOR

The conductivity cell is located beneath a recessed cover on the front panel of the instrument, just below the digital display. In the recess ofthis cover, two short 0.76 mm diameter stainless steel nipples serve as inlet and outlet connections to the cell.

INLET/OUTLET NIPPLES

For measurement, two short lengths (approximately 36 em) of microbore plastic tubing are slipped over the stainless steel nipples. One of these tubes is from the Macroduct sweat collector and contains the sweat specimen to be analyzed. The other tube is the Take-Up Tube (Wescor Catalog SS-044). During analysis, the sweat specimen is transferred from the Macroduct tube into the Take-Up Tube via the conductivity cell. As the sweat specimen passes through the cell, its electrical conductivity is measured and the result appears on the digital display.

CONDUCTIVITY CELL (beneath cell Cover)

FIGURE 1-2

POWER SWITCH POWER CORD RECEPTACLE MODEL & SERIAL NUMBER

1-1

FUSE(S) (2 on 2201240 volt versions)

SECTION 1

INTRODUCTION Specifications for Model 3100 Sweat· Chek™ Minimum Sample Volume ._.~~!~~.Q!!._._.

.

.

6-10 microliters

._.

.~_~Q!!.b...iLSt~g~~U;~_~~!.a.!i2!1.L ..._._._..._._.._._

Useful Range

0 to 150 mmol/L --.9"i!i~~1 ~~g~..!~.inear ~!!9.!" .-.!=~~~.. !!!~_~% (in ~~.!~ge fro~l_~._~o .!..!Q ~.2.!£!:..l Sample Stabilization Time Approximately 10 Seconds _.~~ll. W~:~_ Tim~ ~..PQ!2~i!P.:~tely 5 minl!!es after 'p-o~er-u'p"". _ Readout 3 Y2 digit liquid crystal display Calibration Reference Standard -------------------------NaCI solution -----------_._-_._-Cell Operating Temperature 39.5°C ± 0.5°C Line Voltage Options* 100 Volts, 50-60 Hz 115 Volts, 50-60 Hz 220-240 Volts, 50-60 Hz Power 5 Watts Fuse(s) 1/8 Amp Time-Lag 3AG (100 volts) 1/8 Amp Time-Lag 3AG (115 volts) 1/16 Amp**Time-Lag 3AG (220-240 volts) (2 fuses required for 220-240 volt units) Dimensions 10 x 20--_._ cm x 14 cm __._._--_._------_ _ . -_.._-----_._---_._._-----_._._----_cm ...•..••••• _-_._ Weight 1.0 kg *Make certain the voltage specification on the rear panel of the Analyzer matches the local line voltage before connecting to electrical power. **100 milliampere fuses can be substituted.

Accessories and Supplies SweatoChek™ is furnished with all materials necessary to use the instrument in conjunction with Macroduct sweat collectors including: Quality 1 each -----1 each lQ.Q._~ac1?-_._.

Part Number M2853 SS-040

Description Instruction/Service Manual _. ..._._.._--_..._._--_._._---_._ ..._._90 mmol/L Calibration Check Solution, 90 mL

__

.__.._'I~~.:!!.P- ..I~~~JM!£!2!?.9I.~J~!~~~i0]!1l..~gl.._ #22 Blunt Needle __.~._~~~. ._* ._. J mL S~g~ ._ _ .__._._. _ * Replace syringes from local suppliers. 3 each

§.~-044:

SS-045

1-2

SECTION 2

OPERATION Instrument Preparation 1. The power switch is located on the back of the instrument near the power cord receptacle. When connected to the proper line voltage and turned "on," the power indicator should glow GREEN. The display will read "000". The status indicator will initially glow amber. After approximately five minutes, the status indicator will change to green, indicating that the conductivity cell has reached stable operating temperature. The Analyzer is now ready to accept samples. 2. Attach a length of clean microbore tubing (Wescor catalog number SS-044) to be used for a take-up tube to one of the stainless steel nipples. Either nipple may be used, but we suggest that the right hand nipple be used as the "outlet". Attach the tube containing the specimen for analysis to the opposite nipple, which will serve as the "inlet". Normally, you introduce the sweat specimen into the conductivity cell directly from the Macroduct collection tube. A typical Macroduct sweat collection produces many times the volume of sweat needed for analysis, but in cases where the sweat yield is below average, measurement is possible using 6 to 10 microliters of sweat. However, in such cases, careful and precise technique is mandatory, since positioning of the sample within the cell becomes critical.

FIGURE 2-1

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.

If the sample volume is lower than that required to establish continuity between the electrodes in the conductivity cell (approximately 6 microliters), then no measurement will be possible. However, any reading sustained on the on the digital display for at least a few seconds will be valid. NOTE: Handle the sweat specimen with care prior to analysis to avoid introducing air bubbles into the sweat column. An air bubble in the conductivity cell will prevent accurate measurement.

2-1

SECTION 2

OPERATION Sweat Collection and Preparation of the Specimen The Macroduct® Sweat Collection System manual provides complete instructions for sweat collection. These should be followed rigorously except for removal of the sweat sample, where the procedure is modified slightly as follows: 1. Remove the protective Macroduct cover by inserting a pointed tool such as the nippers supplied with the Macroduct system, into one ofthe cut-out sections and prying upward. 2. In place of the sweat dispenser supplied with the Macroduct system, use the 1 ml tuberculin syringe fitted with a blunt needle, which is supplied with SweatoChek. Position the syringe plunger at mid-point in the barrel. This will allow movement of the plunger in either direction. ONCE THE SYRINGE-TO-TUBE CONNECTION IS MADE, GUARD AGAINST ANY INADVERTENT MOVEMENT OF THE PLUNGER AS THIS MAY RESULT IN A LOSS OF THE SPECIMEN.

FIGURE 2-2

3. Press the collector VERY FIRMLY against the skin to transfer any residual sweat to the spiral tube (if the collector has been attached with sufficient strap pressure, this will not increase the sweat volume in the tube by more than 2-3 rom). FIGURE 2-3

4. Attach the syringe to the outer end of the Macroduct tubing by rotating the needle into the tubing as shown in Figure 2-2. 5. Holding the END OF THE SPIRAL TUBING (not the syringe), as shown in Figure 2-3, fully extend the spiral by pulling it away from the collector body so that the connection between the tubing and the collector body is accessible. Then sever the tubing as closely as possible to the collector body as shown in Figure 2-4.

FIGURE 2-4

2-2

SECTION 2

OPERATION 6. After you separate the collection coil from the Macroduct collection body, gently draw the sweat further into the tubing so that the tightly coiled end of the tubing can be trimmed off (do not draw the sweat specimen into the syringe). This will simplify connecting the tubing to the nipple ofthe conductivity cell. Push the tubing "straight on" as shown in Figure 2-1.

Previously Collected Sweat or Standard Solution If the sweat specimen to be tested has already been transferred to a storage cup, or if you wish to run the Calibration Check Solution or water into the Analyzer, simply attach a spare Take-Up Tube to the syringe. Position the syringe plunger near mid-point, and carefully withdraw the plunger to bring the specimen into the tube. Use only new, clean tubing that is certified solute-free to avoid measurement errors (Take-Up Tubes supplied by Wescor meets this requirement).

FIGURE 2-5

Measurement Connect the end of the specimen tube to the inlet nipple of the conductivity cell (either nipple may be used). Transfer the specimen into the cell by gently moving the syringe plunger into its barrel (Figure 2-5). When the liquid column of the specimen makes contact with the cell electrode, the digital display will rise quickly from its zero reading. If the movement ofthe liquid column is then stopped, the specimen rapidly equilibrates to the cell temperature. Motion of the liquid column will bring cooler liquid into the conductivity cell, briefly producing a lower reading, but the reading will quickly stabilize whenever motion ceases. A slight variation in conductivity from the beginning to the end of a large-volume sweat sample is normal (see Section 3). When the liquid column of the specimen loses contact with the first cell electrode, the reading will fall to zero. If desired, the specimen can be drawn back into the cell to repeat the measurement. Provided that the plunger is moved smoothly and gently, the specimen can be transferred in and out of the conductivity cell for repetitive measurements as many times as desired. On the other hand, abrupt, jerky movements of the plunger will tend to separate the liquid column, and the resultant air bubbles will interfere with readings as they pass through the cell. 2-3

SECTION 2

OPERATION System Operating Checks

Cleaning the Conductivity Cell nnn

IMPORTANT: After testing each specimen, rinse the conductivity cell with at least one syringe full ofdeionized water. When all residual salt has been flushedfrom the cell, the reading on the display will be "000" (with pure water in the cell). Then remove the water by using the syringe to push air through the cell. Finally, pump the syringe plunger to purge remaining droplets ofwater from the cell. This procedure is necessary to ensure accuracy in the subsequent measurement.

The 3100 SweatoChek is factory-calibrated and under normal conditions should not require further adjustment. Calibration ofthe instrument can be checked using a valid* Calibration Check Solution (SS-040) such as that initially supplied with the instrument. IF THE CELL IS CLEAN AND FREE OF RESIDUAL SALT OR WATER, the reading given by the Analyzer should agree with the specified molarity ofthe standard solution within ± 2 mmol/L. Ifrecalibration should become necessary refer to Section 4. SweatoChek's conductivity cell has an extremely stable response characteristic that is virtually linear through the critical range from 75 to 110 mmol/L. At extremely low ranges, there will be a slight positive error in the reading, and at extremely high ranges, negative error. These errors will not invalidate the diagnostic result. The main purpose of the calibration check is to ascertain that the temperature of the cell is within the correct range and that electronics are otherwise functioning normally. A reading that agrees with the labeled value of the standard solution indicates correct overall performance to a very high level of confidence. Further testing is not normally necessary.

Never allow any liquid to remain in the conductivity cell after measurements are complete. Aside from the risk of introducing a measurement artifact in the next procedure, damage may occur if the instrument is inadvertently exposed to freezing temperatures. This could conceivably happen if SweatoChek were being transported to a remote testing site during wintertime. To avoid damage to the cell or other sensitive electronic components, the instruments should be protected from exposure to extremes of heat or cold.

If you want a positive and/or negative control value, Wescor Optimol™ Osmolality Ampule Standards can be employed. The corresponding values of molarities and expected readings are as follows:

Wescor Catalog Number Solution Osmolality Solution Molarity Expected Reading

Positive Control OA-029 290mmol/kg 156mmol/L 140-156 mmol/L

Negative Control OA-OIO 100mmol/kg 53 mmol/L 53-60 mmol/L

CAUTION! * The concentration of any standard NaCI solution will increase with exposure to the atmosphere. Do not trust the labeled value ifthe exposure history of the container is unknown to you.

2-4

SECTION 3

INTERPRETATION OF RESULTS Background

These investigators concluded that conductivity can be a reliable indicator to either rule out cystic fibrosis (normal result) or to provide laboratory confirmation of the physician's clinical diagnosis of cystic fibrosis.

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. A diagnosis of CF will always be based upon clinical findings and observations, but the "laboratory· diagnosis" or "sweat test", performed properly, provides valuable quantitative corroboration of the physician's clinical diagnosis.

The designs of earlier sweat conductivity measuring instruments were lacking in terms of specimen handling, calibration stability, and measurement resolution. The SweatoChek Sweat Conductivity Analyzer with its controlled temperature measurement cell, flow through operation, and wide-range digital readout, is a modem adaptation of a proven analytical method. One experienced investigator, commenting on SweatoChek stated, "If this machine is kept clean, it gives results that are every bit as reliable as an analysis for sodium or chloride"(l4).

Historically, the "sweat test" has been characterized by a high incidence of both positive and negative false results, with false positives predominating. In the professional literature (3,4,5) pungent criticism has been targeted upon various commercial systems that purport to simplify one or more of the three steps in the procedure, Le. SWEAT INDUCTION, SWEAT COLLECTION and SWEAT ANALYSIS. Most of the errors have been associated with the collection phase of the test. Webster's comprehensive review of quantitative sweat testing, from the early 1950's through 1983, identified error factors concomitant to each of these methods (6).

The Sweat Chek has been conditionally approved by the CF foundation for CF screening (IS). The foundation recommends that any result higher than 50 mmol/L be corroborated by analysis for chloride and ion concentration to exclude CF from the possible diagnosis. Results of 50 mmol/L or lower indicate normal sodium chloride and serves as a basis to exclude CF.

Although numerous sweat testing systems have been marketed, the Cystic Fibrosis Foundation of America has approved only two methods of sweat collection proven to be error-free through exhaustive clinical trials. They are the original pad absorption method of Gibson and Cook (7) and the Wescor Macroduct® Sweat Collection System (8,9) both of which are approved as part of the "Quantitative Pilocarpine Iontophoresis Test (QPIT)". The third phase of the sweat test, analysis~ was limited to chloride ion assay in laboratories ofthe early 1950's. Today, laboratory technologists may choose from a number of alternative analytical methods, including anion assay, cation assay, osmolality, or electrical conductivity. The SweatoChek™ Sweat Conductivity Analyzer measures the electrical conductivity of the specimen. Licht (10), Gibson (11), Phillips (12), Shwachman (13) and others conducted extensive investigations concerning the feasibility of conductivity as an alternative method of sweat analysis.

3-1

SECTION 3

INTERPRETATION OF RESULTS It has been shown that the concentration of electrolytes decreases slightly as sweating continues in time (11). If the sweat yield during collection is 30 microliters or more (typical yield is 50 to 60 microliters in 15 minutes using Macroduct), then a slight increase in the reading may be observed as the sweat column passes from the Macroduct collection tube through the conductivity cell into the Take-Up Tube. The variation will be small in comparison with the difference between normal and abnormal sweat, and thus will not confound the diagnosis.

Units of Measure and Clinical Ranges In addition to sodium and chloride ions, sweat also contains significant concentrations of potassium and lactate ions. This poses a problem concerning the selection of a reference or calibration solution but sodium chloride solutions serve well if allowance is made for the other electrolytes. Thus, the reference ranges for conductivity in normal and abnormal groups, in terms of sodium chloride standards, will differ from those established for specific assay of chloride or sodium ions.

Among the patient populations mentioned above, data on cWoride ion assay and sodium plus potassium ion assay, determined simultaneously with the conductivity data, enables linear regression analysis:

SweatoChek has undergone extensive clinical evaluation in studies over 5 years and involving 1090 patients (16). The data is summarized in Table 3-1. From these data, it can be reasonably concluded that the majority ofnormal values will fall below 70 mmol/L, with the majority of positive values above 95 mmol/L.

Chloride Ion Concentration Vs. Sweat Conductivity (514 Patients r = 0.974) CI- = 0.961C - 15.21 Sodium + Potassium Ion Concentration Vs. Sweat Conductivity (514 Patients r = 0.987) Na+ + K+ = 0.974C - 1.49 Macroduct CI Concentration (mmol/L) Vs. Gibson-Cooke Pad Absorption CIConcentration (mmol/L) (1014 patients r = 0.989) CI- = 0.989 (X) + 0.399 x = CI- mmol/L C = equivalent NaCI in mmol/L

One experienced investigator (14) has suggested that a conservative defmition of "equivocal range" is between 70 and 100 mmol/L. Only a small percentage of patient's will fall into the equivocal range. Caution should be used in interpreting any result in the "equivocal" region between 70 and 95. Careful assessment of a patients general state ofhydration, other clinical signs/symptoms, family history ofCF, and any other mitigating factors should all be considered. Retesting, along with alternative methods of analysis, such as chloride or sodium ion assay, may be helpful in resolving an equivocal sweat test result. One study suggests that the Na:CI ratio can be useful in differentiating CF from the non-CF subjects whose sweat test results are otherwise equivocal (17).

Table 3-1 Clinical Ranges, Sweat Conductivity as Equivalent NaCI (mmol/L) Number of Patients Mean Value Standard Deviation Observed Range

Non CF 471 33.4 11.2 13-87

Equivocal* 1 87 NA NA

CF 43 113.1 9.9 90-136

*The "eqUivocal" datum above was from a9 "'h year old patient. Simultaneous chloride ion assay also fell in the "equivocal" range with CI- = 59 mmol/L. The clinical diagnosis in this case was non-CF. 3-2

SECTION 3

INTERPRETATION OF RESULTS References L

di Sant' AgnesePA, Darling RC, Perera GA, SheaR Sweat electrolyte disturbances associated with childhood pancreatic disease. Am J Med 1953;15:777-784.

2.

Clarke JT, Elian E, Shwachman H. Components of sweat. Am J Dis Child 1961;101490.

3.

Gibson LE. The decline of the sweat test. Clin Pediatr 1973;12:450.

4.

Rosenstein BJ, Langbaum TS, Gordes E, Bruislow SW. Cystic Fibrosis: problems encountered with sweat testing. JAMA 1978;1987:240.

5.

Denning CR, Huang NN, Cuasay LR, Shwachman H, Tocci P, Warwick WJ, Gibson LE. Cooperative study comparing three methods ofperforming sweat tests to diagnose cystic fibrosis. Pediatrics 1980; 66:752.

6.

7.

8.

- . - 9.· Carter EP,Barrett AD, Heeley AF, Kuzemko JA. Improved sweat test method for the diagnosis of cystic fibrosis. Arch Dis Child 1984;59:919-922. 10. Licht TS, Stem M, Shwachman H. Measurement of the electrical conductivity of sweat. Clin Chem 1957;3:37. 11. Gibson LE, di Sant' Agnese PA. Studies of salt excretion in sweat. Relationships between rate, conductivity, and electrolyte composition of sweat from patients with cystic fibrosis and from control subjects. J Pediatr 1963;62: 855. 12. Phillips WR. Electrical conductivity of sweat. A simple home-assembled apparatus. Pediatrics 1963;32:89. 13. Shwachman H, Dunham R, Phillips WR. Electrical conductivity of sweat. A simple diagnostic test in children. Pediatrics 1963;32:85.

Webster HL. Laboratory diagnosis of cystic fibrosis. CRC Crit Rev in Clin Lab Sci 1983;18:313-338.

14. Gibson LE. Private communication Loyola University Medical Center, Chicago, IL, August 1994.

Gibson LE, Cooke RE. A test for concentration of electrolytes in sweat in cystic fibrosis of the pancreas utilization pilocarpine by iontophoresis. Pediatrics 1959;23:545.

15. Beall Robert J. Memo to CF Center Directors. January 1990.

Barlow WK, Webster HL. A simplified method of sweat collection for diagnosis of cystic fibrosis. In Lawson D, ed., Cystic fibrosis: horizons, Proceedings of the 9th International Cystic Fibrosis Congress, Brighton, England, June 9-15,1984, New York, NY: John Wiley & Sons, 1984:204.

16. Hammond KB, Turcios NL Gibson LE. Clinical evaluation of the Macroduct sweat collection system and conductivity analyzer in the diagnosis of cystic fibrosis. J Pediatrics 1994;124:255-260. 17. HammondKB, Ask C, WattsK. Use of sweat "unmeasured anion" and NaCI ratio in the diagnosis of cystic fibrosis. Pediatric Pulmonology 1987;Supplement 1:146.

3-3

SECTION 4

SERVICE Instrument Calibration The instrument must be calibrated ifthe conductivity cell has been replaced or ifyou determine that recalibration is needed (see System Operating Checks, Section 2, page 2-4). Two common factors can influence the reading, so before performing recalibration, be sure to check the following: 1.

RESIDUAL SOLUTE OR WATER IN THE CONDUCTIVITY CELL If the cell is not rinsed thoroughly after testing sweat or saline solutions, residual salt may be left in the cell. This tends to increase the reading on a subsequent specimen. Conversely, ifrinse water is not purged from the cell after rinsing, it may dilute a subsequent specimen, causing a decreased reading. Making certain the cell is clean and dry before assessing calibration with the Calibration Check Solution. FIGURE 4·1

2.

CONCENTRATED CALIBRATION CHECK SOLUTION NaCI standard solutions tend to concentrate whenever the cap is removed from the bottle and the contents are exposed to the atmosphere. If you doubt the validity of the Calibration Check Solution, verify using a freshlyopened bottle before proceeding.

Ifyou have eliminated the possibility of error from either of the above sources, and recalibration is indicated, the procedure is as follows: 1.

REMOVE THE CELL COVER

A. Remove the small Phillips-head screws located in the recess of the cover to the side of the nipples (Figure 41). FIGURE 4-2

B. Check to see that the nipples are parallel with one another and perpendicular to the cover. C. Carefully lift the cover away from the front panel, sliding it off the nipples as it comes forward (Figure 42). NOTE: Ifthe cover fits tightly in the panel opening, it may be necessary to insert a knife blade under the bezel of the cover to help pry it away from the panel. Gradually work your way around the bezel to lift the cover evenly and prevent binding.

4-1

SECTION 4

SERVICE 2.

INJECT CALffiRATION CHECK SOLUTION INTO THE CONDUCTIVITY CELL

NOTE: Make certain that no liquid gets inside the instrument during these procedures. A. Connect a new Take-Up Tube (Wescor catalog number SS-044) to the outlet nipple of the cell (either nipple can be used).

B. Attach a second new Take-Up Tube to the blunt-end needle ofthe syringe, and draw a specimen directly from the bottle of Calibration Check Solution into the tube (do not draw solution into the syringe). Replace the bottle cap promptly.

FIGURE 4-3

C. Connect the syringe tube to the inlet nipple of the cell (Figure 4-3). D. Gently move the syringe plunger to transfer the Calibration Check Solution into the conductivity cell. The reading will stabilize in approximately 10 seconds (Figure 4-4). 3.

ADJUST CALffiRATION Use a small flat-blade screwdriver at the point labeled "CAL", to adjust the instrument reading to agree with the assayed molarity ofthe Calibration Check Solution (Figure 4-5).

4.

CLEAN THE CONDUCTIVITY CELL Flush the conductivity with deionized water, followed by bursts of air to purge any remaining droplets (see Cleaning the Conductivity Cell, page 2-4).

5.

RE-INSTALL THE COVER Carefully align the cell cover with two nipples so that the nipples protrude through the holes without binding. Gently press the cover down until it seats in the front panel. Install the cover screws, but do not over tighten. The instrument is now ready for use.

FIGURE 4-4

FIGURE 4-5

4-2

SECTION 4

SERVICE Replace the Conductivity Cell If one of the stainless steel nipples ofthe conductivity cell breaks, you must replace the cell (Wescor RP-111) Use the following procedure: 1.

SWITCH THE INSTRUMENT OFF AND DISCONNECT LINE POWER

2.

REMOVE THE CELL COVER Refer to step 1A under "REMOVE THE CELL COVER" page 4-1.

3.

REMOVE THE CONDUCTIVITY CELL

NOTE: Do not remove the two small screws that are located near the nipples on the printed circuit board ofthe cell assembly. The cell is held in place by a circuit board connector. Carefully insert needle-nose pliers in the holes provided in the circuit board Disconnect the circuit boardfrom the connector by gently gripping the pliers and pulling the circuit board straight out (Figure 46). Do this carefully to avoid damage to the circuit board or the connector. 4.

5.

FIGURE 4-6

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. Gently press the cell down until it seats against the connector.

FIGURE 4-7

CALIBRATE THE NEW CONDUCTIVITY CELL Follow the procedure under "Instrument Calibration" including replacement of the cell cover.

FIGURE 4-8

4-3

SECTION 4

SERVICE Factory Assistance The Wescor Service Department is committed·to quickly and efficiently resolve any problem that may arise with the operation or performance ofthe SweatoChek Analyzer. In case of any difficulty that cannot be resolved through the procedures set forth in this manual, a request for assistance will be given courteous, prompt attention. Customers within the United States are encouraged to contact us by telephone for consultation and advice. Many of our authorized dealers outside the United States provide full local service and support for Wescor instruments. In addition, the factory service department is accessible from anywhere in the world by fax.

Wescor, Inc 459 South Main Street Logan, Utah 84321 USA TELEPHONE: 801 752 6011 extension

TOLL FREE: 800 453 2725

0 171 172

(Operator) (Orders) (Service)

extension 0 171 172

(Operator) (Orders) (Service)

FAX: 801 752 4127

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