WT-20 Conductivity TDS Meter Users Manual • Mode d’emploi • Bedienungshandbuch • Manual d’Uso • Manual de uso
Conductivity TDS Meter Users Manual July 2009, Rev.1 ©2009 Amprobe Test Tools. All rights reserved.
Limited Warranty and Limitation of Liability Your Amprobe product will be free from defects in material and workmanship for 1 year from the date of purchase. This warranty does not cover fuses, disposable batteries or damage from accident, neglect, misuse, alteration, contamination, or abnormal conditions of operation or handling. Resellers are not authorized to extend any other warranty on Amprobe’s behalf.
Non-Warranty Repairs and Replacement – US and Canada Non-warranty repairs in the United States and Canada should be sent to a Amprobe® Test Tools Service Center. Call Amprobe® Test Tools or inquire at your point of purchase for current repair and replacement rates.
WT-20 Conductivity TDS Meter 10 1 9 11 7 2 3 4 5 6 8 1) Battery Cover 2) Lcd Display 3) Power / Set Key 4) Hld / Cal / Down Key 5) Mode / Up Key 6) Electrode Cover 7) Conductivity Reading (unit: uS or mS ) or TDS Reading (unit: ppt or ppm) 8) Display temperature in either degree Celsius or degree Fahrenheit 9) Calibration Mode Indicator 10) Freeze Display 11) Low Battery Indicator POWER / SET - Power on/off, Enter setting mode (push 2 sec), Enter while in setting mode.
CONTENTS SYMBOLS........................................................................... 2 UNPACKING AND INSPECTION ........................................ 2 INTRODUCTION................................................................. 3 Features......................................................................... 3 OPERATION........................................................................ 3 Auto Power Off ............................................................ 4 Setup . ................
SYMBOLS � Caution! Refer to the explanation in this Manual � Conforms to relevant Australian standards � Complies with European Directives = Do not dispose of this clamp meter as unsorted municipal waste. Contact a qualified recycler for disposal. �WARNING and PRECAUTIONS • Do not make the air bubble adhere on the electrode. That may cause inaccurate reading. • Do not operate the meter in flammable liquid.
INTRODUCTION Congratulations on your purchase of WT-20 Conductivity TDS meter. A convenient instrument to measure water conductivity, TDS and temperature. Features • • • • • • IP65 Waterproof housing. Dual display with ATC (°C / °F switchable) Data hold to freeze display. Low battery indicator. Auto power off. One touch only for calibration. Operation 1. Remove the electrode cover to expose the electrode out. 2. Press “POWER” to power on.
7. Dip the probe into the sample container. Make sure no air bubbles trapped in the slot of the probe. To remove air bubbles, give the probe a gentle stir. Making sure the electrode tip is submerged when you stir it. 8. Stir the probe gently in the sample to create a homogenous sample. Allow a few seconds to reach temp. equilibrium. Wait about 15 minutes can get a stable reading. 9. The unit of conductivity will flash on the LCD to indicate the meter is in measurement mode.
Setup The advanced setup mode lets you customize your meter. 4 types parameter are available. P1.0: temperature parameter setting (t) P1.1: Change temperature unit (tUt) P1.2: Normalization temp.(tnr) P1.3: Temp. Coefficient (tCo) P2.0: TDS factor setting P2.1: Setting TDS factor (tds) P3.0: Reset meter (rSt) P3.1: Reset P4.0: Review Calibration Info. (CAL) P4.1: Review range 1 calibration information P4.2: Review range 2 calibration information P1.1: Change temperature unit (tUt): 1.
P1.3: Temp. Coefficient (tCo) In temp. coefficient adjustment, press “q“or “p“ to change the temperature coefficient from 0.0 to 4.0. Press “SET“ to confirm or press “SET“ more than 2 sec to return to P1.0 without confirming. P2.1: Setting TDS factor(tds): In P2.0, press “SET“ to enter P2.1. The factor will flash on LCD. Press “q“or “p“ to change factor from 0.40 to 1.00. Press “SET“ to confirm or press “SET“ more than 2 seconds to return to P2. 0 without saving. P3.
Calibration Mode (CAL) Selecting a calibration standard For best results, select a conductivity or TDS standard near the sample value you are measuring. Alternatively, use a calibration solution value which is approximate 2/3 of the full scale of the measurement range you plan to use. For example, in the 0 to 1999 uS range, use 1413 uS solution for calibration. DO NOT reuse the calibration solution.
6. Dip the rinsed probe into the second container. Tap probe on the bottom of container to remove air bubbles. Wait about 15 mins to make the probe stabilize to the solution temperature. 7. Press “CAL“ more than 2 seconds to begin calibration. The conductivity value of solution will blink on LCD. 8. Press “p“ and “q“ to change the value in order to match the value to the standard solution(solution must be referred to normalization temp. 20oC if P1.2 is adjusted as 20 oC).
TDS Calibration Option1: Using TDS standards 1. Insert the probe into demineralized or distilled water for about 30 minutes to rinse the probe 2. Select the TDS standard for calibration. The factory default setting of the TDS conversion factor is 0.50. You can improve the calibration accuracy by setting the TDS factor before starting the calibration. Please refer Appendix A for more information of TDS conversion factor. 3. Pour enough solution into two separate & clean containers. 4. Turn on the meter.
SPECIFICATION Range : 0~1999uS/0~1999ppm or 0~19.99mS/0~19.99ppt Resolution : 1uS/ppm or 0.01mS/ppt Accuracy : 1% Full Scale±1digit TDS factor : 0.40~1.00 Calibration Standard : (0.2~1) * Full Scale Range ATC : 0~50°C Temperature Accuracy : ±0.5°C Temp. Coefficient : 0~4.0% per degree C Normalization Temp. : 20 or 25°C Operation temp. : 0~50°C Power Requirements : 4pcs1.5V(Type: A76 or LR44) � - EMC: Conforms to EN61326-1.
MAINTENANCE AND REPAIR If there appears to be a malfunction during the operation of the meter, the following steps should be performed in order to isolate the cause of the problem. 1. Check the battery. Replace the battery immediately when the “ ” symbol appears on the LCD. 2. Review the operating instructions for possible mistakes in operating procedure.
BATTERY REPLACEMENT 1. Turn off the meter and loose the battery cover in counter-clockwise direction. 2. Replace the old batteries with four new LR44 button cells. 3. Put back the battery cover and turn it tightly. the Red LED Low Battery indicator illuminates. The batteries should be replaced as quickly as possible.
TROUBLE SHOOTING Power On But No Display • Make sure you press power key more than 100 mS. • Check the battery conditions and replace if necessary • Move batteries away for one minute and then re-install. Display Disappear • Check whether the low battery icon is appeared before the display is off. If yes, replace with new batteries Air Bubbles Adhere On Electrode • Stir the electrode completely and better to dip the electrode into solution at oblique angle.
“E03“ Conductivity value is over the range limit (19.99mS) or meter is damaged. • Put the meter in standard solution. If E03 still appears, send back for repair. “E04“ Caused by temp. reading error • Refer to error code of temp. After solving the error of temp, E04 will disappear. Parameter: TDS “- - -“ Meter is in manual range 1 however the measured value is higher than 1999*TDS factor ppm • Press “p” more than 2 seconds to change the range to range 2 or to auto ranging. “E04“ Caused by temp.
Appendix A: Conductivity to TDS Conversion Factors TDS KCL Conductivity at 25 °C ppm Factor TDS (NaCL) TDS (442) ppm Factor ppm Factor 23μS 11.6 0.5043 10.7 0.4652 14.74 0.6409 84μS 40.38 0.4807 38.04 0.4529 50.5 0.6012 447μS 225.6 0.5047 215.5 0.4822 300 0.6712 1413μS 744.7 0.527 702.1 0.4969 1000 0.7078 1500μS 757.1 0.5047 737.1 0.4914 1050 0.7 2070μS 1045 0.5048 1041 0.5029 1500 0.7246 2764μS 1382 0.5 8974μS 5101 0.5685 4487 12,880μS 7447 0.
Actual Conductivity: Value measured using a properly calibration Conductivity/TDS/Temperature meter. Both the actual TDS and the actual conductivity values must be in the same magnitude of units. For example, if the TDS value in is ppm, the conductivity value must be in µS; if the TDS value is in ppt, the conductivity value must be in mS. Check this number by multiplying the conductivity reading by the factor in the above formula and the result is the TDS in ppm.
Linear temperature correction: In moderately and highly conductive solutions, temperature correction can be based on a linear equation involving a temperature coefficient (q). The coefficient is usually expressed as a conductivity variation in % / °C. Linear temperature correction is used, e.g. for saline solutions, acids and leaching solutions.
T2 should be selected as a typical sample temperature and should be approximately 10°C different from T1. The temperature coefficients of the following electrolytes generally fall into the ranges shown below: Acids: 1.0 - 1.6% / °C Bases: 1.8 - 2.2% / °C Salts: 2.2 - 3.0% / °C Drinking water: 2.0% / °C Ultrapure water: 5.2% / °C Average temperature coefficients of standard electrolyte solutions expressed as %/°C of the conductivity value at 25°C Temp. range °C KCl 1 M 15-25 1.725 1.
