Instruction Manual pHPLUS DIRECT pH/mV/ISE Meter Code 5-1936
PREFACE This instruction manual serves to explain the use of the pHPLUS DIRECT meter. It functions in two ways: first as a step by step guide to help you operate the meter; second, it serves as a handy reference guide. This manual is written to cover as many anticipated applications of the pHPLUS DIRECT meter as possible. If there are doubts in the use of this meter, please do not hesitate to contact the LaMotte Tech Service Department.
Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.1 Description of Keypad Functions . . . . . . . . . . 2.2 Description of LCD Annunciations . . . . . . . . 2.3 Inserting & Removing the Rubber Boot . . . . . . 2.4 Inserting New Batteries . . . . . . . . . . . . . . . 2.5 Battery Replacement . . . . . . . . . . . . . . . . 2.6 Connecting the Electrode and Temperature Sensor 2.
1. INTRODUCTION Thank you for purchasing the pHPLUS DIRECT meter. This microprocessor-based handheld meter is economical and easy to use. It has a large custom LCD (Liquid Crystal Display) for clear and easy reading. The pHPLUS DIRECT measures pH, mV (ORP), temperature and ion concentration of various ions (mono and di valence) with ion selective electrodes (ISEs).
2. GETTING STARTED 2.1 Description of Keypad Functions The pHPLUS DIRECT has six keys on its splash-proof keypad with tactile feedback. The keys include ON/OFF, HOLD/ENTER, CAL, MODE, p and q keys. ON OFF MODE CAL Powers meter on and off. Meter starts up in the mode that you were in before turning the meter off. Selects measurement mode for Ion, mV, pH and Temperature. Allows calibration for Ion, pH, mV or Temperature, or to abort calibration without confirming any set value.
2.2 Description of LCD Annunciators The meter has a large custom LCD that consists of 3½-digit segments and operation annunciators for pH, mV or °C (Temperature). Note that there is no annunciator shown in the Ion mode. Other annunciators include “HO” (when the HOLD function is activated) and “LO” (low battery condition). 2.3 Inserting & Removing the Rubber Boot 1. To remove the meter from the rubber boot, push out the bottom edges of the meter until it is completely out of the boot.
2.4 Inserting New Batteries The battery compartment is found at the back of the instrument. To open the battery compartment, push in the direction of the arrow and lift up the cover. Note the polarity of the batteries before inserting them into position. After replacement, replace the cover and press down until it locks tight. 2.5 Battery Replacement A “LO” annunciator in the LCD alerts you when battery power is running low. Replace the batteries with the type recommended by the manufacturer.
BNC of pH/ORP Electrode or ISE Phono jack of Temperature probe Insert the mini phono jack of the temperature sensor into the socket on the meter. Unplug the phono jack when not in use or when pH is being measured without any temperature compensation. 2.7 Condition the pH Electrode Condition the pH electrode before the first use or if it has not been in use for a long time by soaking it in a container filled with pH 4 buffer solution for at least 1 hour. Rinse with tap water before proceeding. 2.
3. CALIBRATION 3.1 pH Calibration The meter is capable of calibrating up to 3 points using USA or NIST (nSt) pH buffer standards or 2 points with Low Ionic (Pb) pH buffer standards. All new calibration values will automatically override existing data. USA pH 4.01,7.00 and 10.01 NIST pH 4.01, 6.86 and 9.18 Pb pH 4.10 and 6.97 It is recommended that you perform at least a 2-point calibration at room temperature (25 °C) using standard buffers, starting with the first buffer at pH 7.00 (USA), pH 6.
3.2 Selection of pH Buffer Standards You must set the meter to accept either USA, NIST (nSt) or Low Ionic (Pb) pH buffer standard values before calibration. The factory default is USA standard. If you wish to abort this operation press the CAL key at any sequence and the meter reverts to pH measurement mode. 1. Press and hold the MODE key. Switch on the meter using ON key. The display shows “bUF” blinking. 2. Press the ENTER key to get into the buffer selection mode.
3.2.2 pH Calibration using USA standard buffers 1. Pour a known pH buffer standard solution into a clean, dry container, e.g. pH 7.00. Power on the meter and it will automatically enter the measurement mode. Select the pH mode by pressing the MODE key if necessary. 2. Dip both the pH electrode and temperature probes into pH 7.00 buffer solution. Swirl gently and wait for the reading to stabilize (approx. 30 seconds depending on the electrode condition). 3. Press the CAL key to enter the pH calibration mode.
3.2.3 pH Calibration using NIST standard buffers 1. Pour a known pH buffer standard solution into a clean container, e.g. pH 6.86. Power on meter, and it will automatically enter the measurement mode. Select the pH mode by pressing the MODE key if necessary. 2. Dip both the pH electrode and temperature probes into the pH 6.86 buffer solution. Swirl gently and wait for reading to stabilize (approx. 30 seconds depending on the electrode condition). 3. Press the CAL key to enter the pH calibration mode.
3.2.4 pH Calibration using Pb standard buffers 1. Pour a known pH buffer standard solution into a clean container, e.g. pH 6.97. Power on meter, and it will automatically enter the measurement mode. Select the pH mode by pressing the MODE key if necessary 2. Dip both the pH electrode and temperature probes into the pH 6.97 buffer solution. Swirl gently and wait for the reading to stabilize (approx. 30 seconds depending on the electrode condition). 3. Press the CAL key to enter the pH calibration mode.
3.3 Ion Calibration The pHPLUS DIRECT meter is capable of up to 3-point ion calibration (minimum 2 point) with standard solutions to ensure accuracy across the entire range of the meter. To exit calibration after you have first entered into ion calibration, press the CAL key again. No ion calibration values are stored into the meter’s non-volatile memory. Note that ion calibration data is lost once the meter is reset when the batteries are removed and replaced.
3.3.1 Multi-point Ion Calibration 1. If a calibration with a 1.0 ppm standard is desired, the 0.1 ppm calibration can be skipped (see below*). 2. For instance if a 1.0 ppm calibration standard is used, pour a known 1.0 ppm standard solution into a clean container. Power on the meter, and set the meter to Ion measurement mode. 3. Dip the ISE into the 1.0 ppm standard solution. Stir it gently. Press CAL key to enter into calibration mode. 4. The display shows “CA” momentarily followed by “0.1” flashing.
9. Press the ENTER key to confirm the second calibration point (e.g. 10.0 ppm). The display will show the next calibration option, 100.0 ppm. To exit from the 2-point calibration, press the CAL key. The LCD will show “PXX mV” momentarily which is the ISE slope in mV value. The meter then reverts to ion measurement mode. The calibration values are successfully stored into the memory. Otherwise an error message “Er3” will be displayed if the slope of ISE is lower than 15mV/decade or higher than 90mV/decade.
5. To cancel or abort this operation, press the CAL key. Note no new value will be stored into the meter's non-volatile memory. To confirm the calibration, press the ENTER key. The LCD displays “CO” momentarily, and the meter reverts to the measurement mode. 3.4.2 Without Temperature probe (no ATC) If a temperature probe is not used, the meter compensates for the pH response based on a new calibrated temperature value manually set or at 25.0 °C (factory default). 1.
4. MEASUREMENT 4.1 Taking Measurements 1. Before measurement, rinse the pH/ORP electrode or Ion Selective Electrode (ISE) and temperature probe thoroughly with tap or distilled water to remove any impurities on the bodies of probes. 2. Power on the meter using the ON key. Press the MODE key to select the desired mode of operation (pH, mV, Ion or Temperature). 3. Dip both probes gently in the test sample, stir gently and wait for the reading to stabilize. Note the reading.
5. ELECTRODE CARE AND MAINTENANCE For best results, always keep the ISE capped dry and pH/ORP electrode bulb wet. Store the pH/ORP glass bulb with pH electrode storage solution. pH buffers are also suitable. NEVER use deionized water for storage. Wash the probes thoroughly with distilled water after each use. Because the ISE or pH electrode is susceptible to contamination or dirt, clean it every 1 to 2 months depending on extent and condition of use. Clean the pH/ORP electrode using a mild detergent.
7. SPECIFICATIONS Ion Range Resolution Accuracy No. of Calibration Pts pH Range Resolution Accuracy pH Slope Range No. of Calibration Pts Buffer Option Temperature Range Accuracy Temperature Comp. Millivolt Range Resolution 0.01 to 1999 ppm 0.01 ppm for 0.01 to 0.99 ppm; 0.1 ppm for 1.0 to 199.9 ppm; 1 ppm for 200 to 1999 ppm +/- 1% of reading 2 to 3 points (minimum 2 pts) 0.00 to 14.00 pH 0.01 pH +/- 0.01 pH 80 to 120% 1 to 3 points (push-button) pH 4.01, 7.00, 10.01 (USA) pH 4.01, 6.86, 9.
8. ACCESSORIES pH pH Electrode Temperature Probe AC Adapter, 110 V AC Adapter, 220 V Buffer, pH 4.01, 120 mL Buffer, pH 7.00, 120 mL Buffer, pH 10.00, 120 mL Mini Buffer Tablets, pH 4.0, 50 tablets Mini Buffer Tablets, pH 7.0, 50 tablets Mini Buffer Tablets, pH 10.
Instrument Guarantee This Instrument is guaranteed to be free from defects in material and workmanship for a period of one (1) year from the original purchase date. In the event that a defect is found during the warranty time frame, LaMotte Company agrees that it will be repaired or replaced without charge except for the transportation costs. This guarantee does not cover batteries. This product can not be returned without a return authorization number from LaMotte Company.
LaMOTTE COMPANY Helping People Solve Analytical Challenges® PO Box 329 • Chestertown • Maryland • 21620 • USA 800-344-3100 • 410-778-3100 (Outside U.S.A.) • Fax 410-778-6394 Visit us on the web at www.lamotte.
