PREFACE This manual serves to explain the use of the pH 5 PLUS meter. This manual functions in two ways: first as a step by step guide to operating the meter; second, as a handy reference guide. This manual is written to cover as many anticipated applications of the meter as possible. If there are questions about the use of this meter contact the LaMotte Tech Service Department.
TABLE OF CONTENTS 1. INTRODUCTION 2. GETTING STARTED 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 3. CALIBRATION 3.1 3.1.1 3.1.2 3.1.3 3.2 3.2.1 3.2.2 4.
1. INTRODUCTION The pH 5 PLUS 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 pH 5 PLUS measures pH and temperature (°C). Meters include 4 alkaline “AAA” batteries, a rubber boot /stand, instruction manual, and warranty card. Please refer to Section 8 Replacement Parts and Accessories for information on additional accessories and calibration solutions.
2. GETTING STARTED 2.1 Description of Keypad Functions The pH 5 PLUS has four keys on the splash-proof keypad: ON/OFF, HOLD/ENTER, CAL and MODE/INC. ON/OFF MODE/INC CAL HOLD ENTER Powers meter on and off. Meter starts up in the mode that was last used. Increments values during temperature calibration mode. Allows calibration for pH or Temperature, or to abort calibration and return to measure without confirming a value. Freezes the measured reading for easy viewing. Confirms calibration value.
2.2 Description of LCD Annunciators The large custom LCD consists of 3½-digit segments which uses annunciators for pH or °C (Temperature). Other annunciators include “HO” (when HOLD function is activated) and “LO” (low battery condition). 2.3 Inserting & Removing the Rubber Boot/Stand 1. To remove the meter from the rubber boot, push out the bottom edge of the meter until it is completely out of the boot. Ensure that the probe cables are not connected. See Figure 1. 2.
2.4 Inserting New Batteries The battery compartment is found at the back of the instrument. To open the battery compartment, push the cover in the direction of the arrow and lift up. Note the polarity of the batteries before inserting them into position. After the batteries have been replaced, reposition the cover and press down until it locks. 2.5 Battery Replacement The “LO” annunciator on the LCD alerts when battery power is running low. Caution: Power off the meter before changing battery.
2.6 Connecting the Electrode and Temperature Sensor To connect the probe to the meter, align the BNC connector slots with the posts of the meter socket and rotate the connector clockwise until it locks. Do not force the connector. To remove the probe, rotate the connector in a counter-clockwise direction until it unlocks, and slide the connector off the socket. 2.
2.8 Switching the Meter On 1. Press the ON/OFF key. All LCD segments will display momentarily as the meter performs a self-diagnostic test. The meter will display “- - -“ if the meter has not been calibrated or if the meter has been reset. 2. Press the MODE key to choose the desired measurement mode. 3. If a temperature probe is not connected, either 25.0°C (factory default) or the last calibrated temperature value will be displayed.
For a 1-point calibration, the calibration should be performed with a pH buffer value closest to the expected sample value being measured. The meter has automatic buffer recognition that identifies the correct pH buffer values during the calibration. The meter will accept calibration values that are within ±1.0 pH units of the expected value, otherwise the DISPLAY will flash “Er1” and the value will not be accepted. Press CAL to abort the calibration and return to the measurement mode.
5. Allow the reading to stabilize. Press the ENTER key to confirm the calibration. “CO” will be displayed momentarily before reverting to the pH measurement mode. 6. For the greatest accuracy, perform a multiple-point calibration. Repeat step 1 with additional pH buffer calibration standard solutions. 3.1.2 Changing the pH Buffer Group The meter can be calibrated with pH standards of USA, NIST (nSt) or Low Ionic (Pb) pH buffer groups. The factory default is the USA buffer group.
3.1.3 Resetting User Calibrated Values The calibrated pH values can be reset to the factory default using the procedure below. The temperature offset will not be reset using this procedure. To abort the reset, press CAL to revert to the measurement mode. 1. Press and hold CAL while switching the meter on using the ON/ OFF key. The DISPLAY will show “rSt” blinking. 2. Press the ENTER key to confirm. The meter will automatically clear all stored pH calibrations and revert to the measurement mode. 3.
4. Press INC key until the display shows the desired temperature. The meter will allow an adjustable maximum value of ±5 °C from the factory default. 5. To cancel or abort this operation, press the CAL key. To confirm the calibration, press the ENTER key. A new value will be stored in the meter non-volatile memory. The meter will display “CO” momentarily, and then revert to the measurement mode. 3.2.
4. MEASUREMENT 4.1 Taking Measurements 1. Before measurement, rinse the pH probe and temperature probe with clean water to remove any impurities. 2. Power on the meter using the ON/OFF key. Press the MODE key to select the desired mode of operation (pH or Temperature). 3. Dip the probes in the aqueous test sample. Stir gently with the probes and wait for the reading to stabilize. Note the reading. Freeze the displayed if desired—for details refer to Section 4.2 Holding a Reading. 4.
5. ELECTRODE CARE AND MAINTENANCE For best results, store the pH probe bulb wet. Store the pH glass bulb in pH probe storage solution. NEVER use deionized water for storage. Wash probes with clean water after each use. pH probes are susceptible to contamination and dirt. Clean them as needed using mild detergent and warm water. Blot the probe gently with soft tissue paper to dry. Avoid excessive rubbing of the glass membrane and avoid touching it with the fingers. Recalibrate after cleaning. 6.
7. SPECIFICATIONS pH Range Resolution Accuracy pH Slope Range No. of Calibration Pts Buffer Options Temperature Range Resolution Accuracy Temperature Comp. 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, 9.18 (NIST) pH 4.10, 6.97 (Pb) 0.0 to 100.0 oC 0.1 °C ±0.
8. REPLACEMENT PARTS AND ACCESSORIES Item Description Code pH Probe Temperature Probe AC Adapter, 110 mV AC Adapter, 220 mV Buffer, pH 4.01, 120 mL Buffer, pH 7.00, 120 mL Buffer, pH10.00, 120 mL Mini Buffer Tablets, pH 4.0, 50 tablets Mini Buffer Tablets, pH 7.0, 50 tablets Mini Buffer Tablets, pH 10.0, 50 tablets 1904 1909 1726-110 1754 2866-J 2881-J 2896-J 3983A-H 3984A-H 3985A-H 9.
10. RETURN OF ITEMS Should it be necessary to return the meter for repair or servicing, pack the meter carefully in a suitable container with adequate packing material. A return authorization number must be obtained from LaMotte Company by calling 800-344-3100 (US only) or 410-778-3100, faxing 410-778-6394, or emailing tech@lamotte.com. Often a problem can be resolved over the phone or by email.
PO Box 329 • Chestertown • MD • 21620 800-344-3100 • 410-778-3100 • f 410-778-6394 www.lamotte.com 626094-33 3.
