1. Buy a new reading is not stable electrode calibration or calibration error cause the first point: there are air bubbles inside the electrode sensitive film or gel. Display thrown down firmly electrode to remove bubbles (like rejection thermometer like), usually the electrode placed upright 2. Why pH7.00 buffer calibration: (This phenomenon is mainly in the gel electrode LE438 and LE407) resolved 7.02 Reason: At this point the temperature of the buffer solution at about 20 ℃. Buffer pH with temperature changes. 7.00 is the buffer value at 25 ℃, 20 ℃ and should be at 7.02; one hundred percent of the pH meter can automatically correct the effect of temperature on the buffer to ensure accuracy. 3. pH6.86 buffer reason calibrated display 7.00: Choosing the wrong group buffer correct: Re-set the correct buffer group. Cause of the error when setting procedure see the operating manual for a second 4-point calibration: Calibration dropouts. Correction: calibration, just press 'cal' key, do not press any other key. Detailed steps as follows: Step 1 calibration, set the calibration buffer group (domestic b = 3; import b = 2) 2, the electrodes were inserted into the appropriate buffer, and then press the "cal" key 3 until the figure is no longer flashing, it will electrode with deionized water clean after inserting the second buffer, then still press "cal" button, wait for 4 digital no longer flashes, the calibration has been completed, can be measured 5. In the different samples, showed almost no change factor : poor contact electrode and instrumentation; or correct electrode is bad: After shutdown, reconnect the electrode and instrumentation; or replace the electrodes. Calibration of the pH meter is calibrated using known pH value of the solution of the instrument to be tested. pH calibration is generally divided into two kinds: one is the other is a two-point calibration calibration. Which is used to calibrate the zero point calibration, calibrate for symmetry. In addition to calibration of the zero point calibration mode outside OPR instrument, but also to observe the slope is within a given range adjustment, if exceeded, the measure allowed, to be re-calibrated, repeat. In actual production calibration, often using two calibrated manner. Two calibration calibration solution using mainly three kinds: pH = 4.00, pH = 6.86 and pH = 9.18. In actual use, only need to take one of the two kinds can be, but requires the first low-high, that is, the first correction when the calibration solution at a low value, and then to the solution at a high value. To E + H's liquisysS CPM223 / 253, for example, at 6.86 and 9.18 in the calibration, connect the power transmission line after the end of the first clean the pH probe into what the instrument is 6.86 OPR solution? The value input scaling solution in the calibration function menu, press CAL to begin the calibration, the meter displays the measured value at this time, when a stable pH range within ± 0.05 over 10s, a little calibration is complete. Rinse after the probe into the 9.18 solution, OPR instrument calibration method with 6.86 wholesale price, when the pH value is stable within ± 0.05 range over 10s two-point calibration is completed. Check the slope and zero point display OPR instrument display production base, when both are in the set range, the calibration is successful, can be put into use, otherwise the two-point calibration should be repeated until the check slope and zero display are displayed in the set only short success within a given range, pH calibration is a repetitive task, each manufacturer's calibration menu may be different, but the principles and methods are the same, as long as the standard solution is accurate, step right, will be able to calibrate successfully. OPR instrument where good quality, OPR instrument, one hundred to one hundred technology provided by Changzhou Technology Limited. Changzhou Best Technology Limited (www.czbckj.com) strong, credible, in Changzhou, Jiangsu chemical instrumentation industry has accumulated a large number of loyal customers. The company better work attitude and continuous improvement will lead one hundred innovative ideas into technology and you hand into the brilliant, for a better future!