[. . . ] 3 GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 OPERATIONAL GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] ±1 (HI 9812-5 only) Manual, 1-point through offset trimmer EC/TDS Calibration Manual, 1-point through slope trimmer EC/TDS Temperature Automatic from 0 to 50°C (32 to 122°F) Compensation with ß = 2%/°C Probe (included) HI 1285-0 for HI 9812 HI 1285-5 for HI 9812-5 Battery Type 1 x 9V alkaline (IEC 6LR61) Life approx. 150 hours of continuous use Environment 0 to 50°C (32 to 122°F); 100% RH Dimensions 165 x 75 x 45 mm (6. 5 x 3. 0 x 1. 8") Weight 250 g (8. 8 oz. ) 5 OPERATIONAL GUIDE INITIAL PREPARATION Each meter is supplied complete with a 9V battery. Remove the battery compartment cover on the back of the meter and install the battery while paying attention to its polarity. Connect the probe to the DIN socket on the top of the meter by aligning the pins with the socket and pushing in the plug. Always remove the electrode protective cap before taking any measurements and make sure the meter has been calibrated before taking any measurements. Turn the meter on by pressing the ON/OFF key. TAKING pH MEASUREMENTS If the probe has been left dry, soak the tip in HI 70300 storage solution for a few minutes to reactivate it. · To take a pH measurement simply submerge the tip (4cm/1½") of the probe into the sample to be tested. · Stir briefly and wait a couple of minutes for the reading to adjust and stabilize. · If measurements are taken in different samples successively, it is recommended to rinse (clean) the probe thoroughly to eliminate cross-contamination. After cleaning, it is recommended to rinse the probe with some of the next sample to be measured. TAKING EC/TDS MEASUREMENTS · Immerse the tip of the probe (4cm/1½") into the sample to be tested. If possible, use plastic beakers or containers to minimize any EMC interference. · Tap the probe lightly on the bottom of the beaker to remove any air bubbles which may be trapped inside the tip. 6 · Select the appropriate measurement range (EC or TDS). · Wait a couple of minutes for the temperature sensor to reach thermal equilibrium. The display will then show the measurement automatically temperature compensated for temperature with the appropriate indication among the following: "µS" symbol indicates the meter is in EC mode; no symbol indicates the meter is in TDS mode. TAKING TEMPERATURE MEASUREMENTS (for HI 9812-5 only) · Submerge the tip (4cm/1½") of the probe into the sample to be tested. · Stir briefly and wait a couple of minutes for the reading to adjust and stabilize. The display shows the temperature value. Note: If the display shows only a "1" on the far left hand side, the reading is out of range. Note: It is recommended to clean often the probe with HI 700661 Cleaning Solution. Note: After measurements have been completed, the instrument should be switched off, and the probe cleaned and covered with the protective cap. 7 pH CALIBRATION For greatest accuracy, frequent calibration of the instrument is recommended. The instrument should be recalibrated for pH: a) Whenever the electrode is replaced. d) Where extreme accuracy is required. PREPARATION Pour small quantities of pH 7. 01 (HI 7007) or pH 4. 01 (HI 7004) or pH 10. 01 (HI 7010) solution into a clean beaker. To obtain accurate readings, use pH 7. 01 (HI 7007) if you are going to measure neutral or close to neutral samples, pH 4. 01 (HI 7004) if you are going to measure acidic samples or pH 10. 01 (HI 7010) for alkaline measurements. If you need to calibrate to NBS standards, use pH 6. 86 (HI 7006) instead of pH 7. 01 and pH 9. 18 (HI 7009) instead of pH 10. 01. PROCEDURE · Connect the probe and switch the meter on, then press the "pH" key to display pH measurement. · Remove the protective cap from the probe, rinse and immerse it in the buffer and stir gently. [. . . ] The cable used for the connection to the meter must be intact and there must be no points of broken insulation on the cable or cracks on the probe stem or bulb. Rinse off any salt deposits with water. CLEANING PROCEDURE For better accuracy in measurements and to ensure a good performance of the probe, a frequent cleaning is recommended. For this purpose, soak it in Hanna HI 700661 Cleaning Solution for 5 minutes. Any variation introduced by the user to the supplied equipment may degrade the instrument's EMC performance. [. . . ]