Digital Dialysate Meter™ Operation Manual 04 October 11
PLEASE NOTE: Because of our commitment to product improvement, the substance and style of this manual may change. When changes are made, the updated manual is posted for download in PDF format from the Myron L Website: www.myronl.
Instrument Illustration Reference Junction under Glass pH Bulb pH/ORP Sensor Well ORP Electrode pH Glass Electrode Conductivity Cell (Built-in Electrodes) Temperature Sensor pH/ORP Sensor Protective Cap TEST Value Preprogrammed variable conductivity/ TDS ratios LOBATT CAL MEMORY KCl NaCl 442 Time & Date displayed here RATIO Parameters COND ORP %/ C F BUFFER RES pH MΩ KΩ mS µS PPM PPT mV TDS - parts per million free chlorine Displayed here: • Temperature readout • Memory Storage/ Recall
TABLE OF CONTENTS 1 Instrument Illustration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 I. GENERAL WARNINGS AND CAUTIONS . . . . . . . . . . . . . . . . 3 II. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 III. FEATURES and SPECIFICATIONS. . . . . . . . . . . . . . . . . . . . . 6 A. Features . . . . . . . . . . . . . . . . . . .
XI. XII. XIII. XIV. XV. XVI. XVII. XVIII. XIX. XX. XXI. XXII. XXIII. XXIV. XXV. 3. Reloading Factory Calibration (Cond or TDS) . . . . . . . . . . . . . . . . . . . . . 19 4. .pH Calibration (D-6) . . . . . . . . . . . . . . . . . 20 5. .ORP Calibration (D-6) . . . . . . . . . . . . . . . 22 6. .Temperature Calibration . . . . . . . . . . . . . . 22 CALIBRATION INTERVALS . . . . . . . . . . . . . . . . . . . . . . . . . . 23 A. Suggested Calibration Intervals . . . . . . . . . . . . . . 23 B.
I. General Warnings and Cautions For your own safety and the safety of your patients follow these important safety instructions as well as other safety instructions noted throughout this operation manual. WARNING: statements alert the user that serious adverse reactions for the patient are associated with related use or misuse. CAUTION: statements alert the user that the related use or misuse of the device could cause it to be damaged or malfunction.
WARNING: The pH/ORP sensor well must ALWAYS be kept wet with a pH sensor storage solution when not in use. • Allowing the sensor to dry out will damage or ruin it. • NEVER use distilled water or tap water as a substitute for pH sensor storage solution. WARNING: DO NOT use a Digital Dialysate Meter™ in place of the primary sensor controls and/or monitors of the hemodialysis system.
II. INTRODUCTION Thank you for selecting the Dialysate Meter™, one of the Myron L Company’s latest in an increasing line of instruments utilizing microprocessor-based circuitry and SMT manufacturing processes. This circuitry makes the instrument accurate, reliable and very easy to use.
III. • • • • • • • • • • • • • • • FEATURES and SPECIFICATIONS A. Features Download capability with optional wireless communication package ORP mV to ppm free chlorine conversion (D-6) 4 digit LCD displays full 9999 µS/ppm Accuracy of ±1% of reading in a handheld instrument ±.
C. Specification Chart (D-6) (D-6) Free Chlorine **mV to ppm conversion accuracy assumes solution pH of 5-9 and Temperature of 20-30ºC in water sanitized by chlorine only D. Warranty/Service The Myron L Dialysate Meter, excluding the pH/ORP sensor, has a Two (2) Year Limited Warranty. The pH/ORP sensor has a Six (6) Month Limited Warranty for materials and workmanship. If an instrument fails to operate properly, see Troubleshooting Chart, pg. 37-38. The battery and pH/ORP sensor are user-replaceable.
IV. Initial Calibration and Factory Settings CAUTION: The factory settings are not intended to replace calibration with reference solution/buffers. Factory settings do not take into account the current condition of the actual sensor installed in your instrument or any environmental conditions that might exist in your facility. • DO NOT use a Digital Dialysate Meter™ to check the pH or conductivity of dialysate using factory calibration settings.
V. RULES of OPERATION A. Operation Using the instrument is simple: • Individual Cond/Res/TDS or multiple parameter readings may be obtained by filling the cond. cell or the entire sensor area. • Rinse the pH/ORP sensor well (D-6) and/or conductivity cell with test solution 3 times and refill. Temperature and/or measurement extremes will require additional rinses for maximum accuracy. • Press the desired measurement key to start measurement. Pressing the key again restarts the 15 second auto “off” timer.
CAUTION: When using a Digital Dialysate Meter™ to check the conductivity of dialysate, the solution type MUST be set to the NaCl conversion factor. • If the proper solution type is not selected (the NaCl icon is not displayed), see Procedure to Select a Solution, pg. 15. A press of b. RES Key displays resistivity with units on the right. On the left is shown solution type selected for resistivity (ref. Solution Selection, pg. 15).
4. CAL/MCLR Key CAUTION: Unintentionally pressing the CAL/MCLR key while making measurements could inadvertently change the calibration of the instrument by activating either: • The calibration mode (the “CAL” icon will appear on the instrument’s display), or • The solution selection menu (the word “SEL” will appear on the instrument’s display). • If you do accidentally activate either of these features: • DO NOT press either the UP or DOWN keys.
B. Maintenance of the pH/ORP Sensor The sensor well must be kept wet with a solution. Before replacing the rubber cap, rinse and fill the sensor well with Myron L pH Sensor Storage Solution. If unavailable, you can use an almost saturated KCl solution, a saturated solution of table salt and tap water or pH 4 buffer (ref. pH and ORP Practices to Maintain Calibration, pg. 24). NEVER use distilled water. VII.
B. Measuring Resistivity Resistivity is for low conductivity solutions. In a cell cup the value may drift from trace contaminants or absorption from atmospheric gasses, so measuring a flowing sample is required. 1. Ensure pH protective cap is secure to avoid contamination. 2. Hold instrument at 30° angle (cup sloping downward). 3. Let sample flow continuously into conductivity cell with no aeration. 4. Press key; use best reading.
4. Press . 5. Take reading. NOTE: When ppm free chlorine units are selected (ref. VIII. ORP UNIT SELECTION), annunciators alert you when the concentration is outside the specified measurement range. “Or” (over range) will display when the concentration is over the range limit (> 9.9 ppm). “Ur” (under range) will display when the concentration is below the range limit (< 0.2 ppm).
5. Press any parameter key to exit ORP unit preference selection or let the unit time out. ORP unit preference will be saved. NOTE: Free chlorine as determined by the D-6 Dialysate Meter is a measurement of the concentrations of Cl2 , HOCl, and OCl - in solution. The D-6 Dialysate Meter does NOT measure chloramines present in solution. IX. SOLUTION SELECTION A. Why Solution Selection is Available Conductivity, resistivity, and TDS require temperature correction to 25°C values.
NaCl conversion factor. • DO NOT change the calibration solution type unless specifically directed to do so by a member of the technical staff of your facility. NOTE: Check display to see if solution displayed (KCl, NaCl or 442) is already the type desired. If not: 1. Press , or to select the parameter whose solution type you wish to change. 2. Press and hold key for 3 seconds to make “SEL” appear (see Figure 3). For demonstration purposes, all 3 solution types are shown simultaneously. 3.
Proper Handling of Reference Solutions continued from previous page • • DO NOT return used samples to the storage bottle. • This includes any solution poured into secondary containers for use with syringes and pipettes. DO NOT use any solution that is past its expiration date. B. Calibration Intervals There is no simple answer as to how often you should calibrate an instrument. Myron L Digital Dialysate Meters™ are designed to not require frequent recalibration.
Function Solution Recalibrate if Dialysate Meter Reports Below Recalibrate if Dialysate Meter Reports Above Conductivity 7000 µS (KCl) 6930 µS 7070 µS pH 7.0 Buffer 6.96 pH 7.04 pH 10.0 Buffer 9.96 pH 10.04 pH Conductivity 14.00 mS (NaCl) TDS 14.14 mS 442™ Solution 3030 ppm (3000 PPM) 2970 ppm 4.0 Buffer 4.04 pH Once in “CAL” mode, the point, pressing 13.86 mS 3.96 pH key becomes an accept key.
C. Calibration Procedures 1. Conductivity or TDS Calibration a. Rinse conductivity cell three times with proper standard, KCl, NaCl, or 442 (ref. Cond/ TDS Standard Solutions, pg. 39). b. Refill conductivity cell with same standard. NaCl-14.00 is the example used here. c. Press or Then press . NaCl . The “CAL” icon will appear on the display (see Figure 4). d. Press or CAL µS °C COND to Figure 4 step the displayed value toward the standard’s value (the value 14.
a. Press b. Press or . . c. Press key until “FAC” appears and release. d. Press to accept the factory calibration setting. 4. pH Calibration (D-6) ALWAYS calibrate a Digital Dialysate Meter™ pH function at Zero Point with a pH 7.0 buffer solution BEFORE performing either the Acid or Base gain calibration. • The Acid/Base gain calibrations may be done in either order. Read Proper Handling of Reference Solutions, pg. 16, before attempting pH calibration.
NOTES: If a wrong buffer is added (outside of 6-8 pH),“7” and “BUFFER” will flash, and the Dialysate Meter will not adjust. The uncalibrated pH value displayed in step 4 will assist in determining the accuracy of the pH sensor. If the pH reading is above 8 with pH 7 buffer solution, the sensor well needs additional rinsing or the pH sensor is defective and needs to be replaced. 5. Press or until the display reads 7.00.
CAL CAL BUFFER BUFFER Figure 6 pH Figure 7 pH 3. Rinse pH/ORP sensor well and conductivity cell 3 times with acid or base buffer solution. 4. Refill pH/ORP sensor well and conductivity cell again with same buffer solution. 5. Press or 6. Press to accept 2nd point of calibration. Now the until display agrees with buffer value. display indicates the next type of buffer to be used. Single point Gain Calibration is complete. Continue for the 3rd point of Calibration (2nd Gain).
XI. CALIBRATION INTERVALS The Dialysate Meter is designed to not require frequent recalibration. The most common sources of error were eliminated in the design, and there are no mechanical adjustments. Still, to ensure specified accuracy, any instrument must be checked against chemical standards occasionally. A.
B. Calibration Tracking Records for General Use (Not Dialysate) To minimize your calibration effort, keep records. If adjustments you are making are minimal for your application, you can check less often. Changes in conductivity calibration should be recorded in percent. Changes in pH calibration (D-6) are best recorded in pH units. Calibration is purposely limited in the Dialysate Meter to ±10% for the conductivity cell, as any change beyond that indicates damage, not drift.
2. Rinse and fill pH/ORP sensor well with pH Sensor Storage Solution immediately after each use. • NEVER use distilled water or tap water as a substitute for pH Sensor Storage Solution. This will deplete the sensor quickly, significantly decreasing its lifespan. • If pH Sensor Storage Solution is unavailable, use: • An almost saturated KCl solution (preferred) • A saturated solution of NaCl (table salt) and tap water (next best alternative) • pH 4 buffer (least desirable alternative).
3. Press or to scroll to the record location desired (the temperature display alternates between temperature recorded and location number). 4. Press to display time and date stamp. 5. Press any measurement key to leave memory recall or allow to automatically turn off. C. Clearing a Record/Memory Clear After recalling a certain record location, press and hold to clear that memory.
Example shown in Figure 10; 16:05 equals 4:05 PM. CAL 1. Press . 2. Press until the time is displayed, scrolling through stored readings, “PC OFF”, and “CLr ALL” to time, i.e.,“16:05”. 3. Press Figure 10 to initiate. “CAL” will be displayed along with the time (see Figure 10). 4. Press 5. Press or to change the time. to accept the change to the new time. B. Setting DATE Example shown in Figure 11 is in US format, i.e., mo/dy/yr. NOTE: The default format is US.
6. Press or to CAL change the month. 7. Press to accept the change to the new month (see Figure 13). 8. Press the or Figure 13 CAL to change the day. 9. Press to accept the change to the new day (see Figure 14). Figure 14 C. DATE FORMAT “US & International (Int)” 1. Press . 2. Press repeatedly until the format is displayed, scrolling Press to change. Display will now indicate other format 3. through stored readings, “PC OFF”, “CLr ALL”, time, and date to date format.
3. Press repeatedly until you pass the “US” or “Int” date format location. The display will show a “C” or “F” (see Figures 17 and 18). Figure 17 4. Press 5. Press Figure 18 to switch units. to accept unit preference for all temperature readings. NOTE: Tempco will still be shown in %/°C. XV. TOTAL RETURN to FACTORY SETTINGS “FAC SEL” There may come a time when it would be desirable to quickly reset all the recorded calibration values in the instrument back to the factory settings.
XVI. CELL CHECK The cell check verifies the cleanliness of the conductivity/TDS/resistivity sensor. In normal use the cell may become dirty or coated and require cleaning. If the display is showing “.00” when the cell cup is dry, the sensor is probably clean. However, when testing high purity water in resistivity (RES) mode improved accuracy may be desired. No matter what a manufacturer claims, a sensor can and will become contaminated or coated and will therefore require cleaning.
3. Press repeatedly until CAL you pass the “CELL ch” location. The display will show “Auto oFF” (see Figure 23). 4. Press to initiate. “CAL” will be displayed along with “15 SEC” (see Figure 24). 5. Press or Figure 24 CAL to change the time (see Figure 25). Maximum time is shown. 6. Press to accept the Figure 25 change (new time). XVIII. “PC On” Mode “PC On” mode enables data transfer to a personal computer when the wireless communication option is installed. (See page 40, G.
WARNING: Digital Dialysate Meter measurement data transferred to a personal computer using the wireless communication option is for record-keeping purposes only and is not intended for use in making treatment or diagnostic decisions. XIX. CARE and MAINTENANCE Dialysate Meters should be rinsed with clean water after use. Solvents should be avoided. Shock damage from a fall may cause instrument failure. • • • • • • A.
WARNING: The case gasket MUST be flat and inserted all the way into the groove on the top case with NO kinks or twists. • An improperly seated case gasket will allow moisture to leak into case that will damage the instrument. Check the four screws. • Each screw MUST have a small black O-ring around its shaft just under the head. • Take care not to lose or damage the O-rings. Dry Instrument THOROUGHLY. Remove the four (4) bottom screws. Open instrument carefully. Carefully detach battery from circuit board.
• Conductivity • TDS Order model RPR. When ordering, be sure to include the model and serial number of your instrument to ensure receipt of the proper type. E. Cleaning Sensors 1. Conductivity/TDS/Resistivity The conductivity cell cup should be kept as clean as possible. Flushing with clean water following use will prevent buildup on electrodes. However, if very dirty samples — particularly scaling types — are allowed to dry in the cell cup, a film will form. This film reduces accuracy.
• If the pH reading is between 8.0 pH and 6.0 pH, calibrating the sensor (see pH Calibration, pg. 20) will correct the offset. 7. Press to return the instrument to measurement mode without changing the calibration of the instrument. 3. pH/ORP CAUTION: ONLY authorized members of your facility’s maintenance staff should attempt the following procedures. The unique pH/ORP sensor in your Dialysate Meter is a nonrefillable combination type that features a porous liquid junction.
Leaving high pH (alkaline) solutions in contact with the pH sensor for long periods of time is harmful and will cause damage. Rinse such liquids from the pH/ORP sensor well and refill it with Myron L pH Sensor Storage Solution to extend the useful life of the sensor. If unavailable, you can use a saturated KCl solution, pH 4 buffer, or a saturated solution of table salt and tap water, but this should be replaced with storage solution as soon as possible.
XX. TROUBLESHOOTING CHART SYMPTOM POSSIBLE CAUSE Inaccurate pH readings (D-6) • pH calibration needed. No response to pH changes (D-6) • pH/ORP sensor bulb is cracked. • Electromechanical short inside the sensor body. Meter won’t turn ON pH Zero Point calibration will not adjust down to pH 7.0 (D-6) • Contamination from residual pH buffers or samples in sensor well. • Calibration with expired pH buffers. • pH/ORP sensor’s internal KCl solution is depleted or contaminated.
CORRECTIVE ACTION • Check battery connections or replace battery. (See Battery Replacement, pg. 32.) • Recalibrate pH function. (See pH Calibration (D-6), pg. 20.) • Thoroughly rinse sensor well. • Recalibrate using fresh buffers. (See pH Calibration (D-6), pg. 20.) • Replace pH/ORP Sensor. (See pH/ORP Sensor Replacement (D-6), pg. 33.) • Clean and rejuvenate sensor. (See pH/ORP, pg. 35.) • Recalibrate. (See pH Calibration (D-6), pg. 20.) • If no improvement, replace pH/ORP sensor.
XXI. ACCESSORIES A. Conductivity/TDS Standard Solutions Your Dialysate Meter has been factory calibrated with the appropriate Myron L Company NIST traceable KCl, NaCl, and our own 442™ standard solutions. Most Myron L conductivity standard solution bottles show three values referenced at 25°C: Conductivity in microsiemens/ micromhos and the ppm/TDS equivalents based on our 442 Natural Water™ and NaCl standards. All standards are within ±1.0% of reference solutions. Available in 2 oz.
Two colors to choose from: Blue - Model #: UCC Desert Tan - Model #: UCCDT E. Hard Protective Carry Cases Large case with 2 oz. bottles of calibration standard solutions (NACL14.0, 442-3000, 4, 7, & 10 pH buffers and pH Sensor Storage Solution). Model #: PKD Small case (no calibration standard solutions), Model #: UPP F. Replacement pH/ORP Sensor (D-6) pH/ORP sensor is gel-filled and features a unique porous liquid junction. It is user-replaceable and comes with easy-to-follow instructions. Model #: RPR G.
XXIII. MYRON L TECHNICAL SUPPORT If you require assistance with any aspect of the operation and maintenance of this product, please contact the Myron L Company Monday through Friday, from 7 a.m. to 3:30 p.m. Pacific Time. Our technical support staff can be reached quickly by phone at +1-760-438-2021. Alternatively, you can contact us by e-mail: techquestions@myronl.
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Myron L COMPANY 2450 Impala Drive Carlsbad, CA 92010-7226 USA Tel: +1-760-438-2021 Fax: +1-760-931-9189 E-Mail: info@myronl.com techquestions@myronl.com www.myronl.
