User manual HANNA INSTRUMENTS HI 98127

[. . . ] If the repair is not covered by the warranty, you will be notified of the charges incurred. If the instrument is to be returned to Hanna Instruments, first obtain a Returned Goods Authorization Number from the Customer Service department and then send it with shipment costs prepaid. When shipping any instrument, make sure it is properly packaged for complete protection. US DESIGN PATENT D462, 024 GENERAL DESCRIPTION HI 98127 and HI 98128 are waterproof pH and temperature meters. The housing has been completely sealed against humidity and designed to float. [. . . ] · If measurements are taken in different samples successively, rinse the probe thoroughly to eliminate cross-contamination; and after cleaning, rinse the probe with some of the sample to be measured. pH: Temp: CALIBRATION For better accuracy, frequent calibration of the instrument is recommended. In addition, the instrument must be recalibrated whenever: a) The pH electrode is replaced. Calibration procedure From normal measuring mode, press and hold the /MODE button until OFF on the secondary LCD is replaced by CAL. The LCD enters the calibration mode displaying "pH 7. 01 USE" (or "pH 6. 86 USE" if the NIST buffer set was selected). After 1 second the meter activates the automatic buffer recognition feature. If a valid buffer is detected then its value is shown on the primary display and REC appears on the secondary LCD. If no valid buffer is detected, the meter keeps the USE indication active for 12 seconds, and then it replaces it with WRNG, indicating the sample being measured is not a valid buffer. · For a single-point calibration with buffers pH 4. 01, 9. 18 or 10. 01, the meter automatically accepts the calibration when the reading is stable; the meter displays the accepted buffer, with the message "OK 1". After 1 second the meter automatically returns to the normal measuring mode. If a single-point calibration with buffer pH 7. 01 (or pH 6. 86) is desired, then after the calibration point /MODE button must be has been accepted the pressed in order to return to normal mode. After the button is pressed, the meter shows "7. 01" (or "6. 86") - "OK 1" and, after 1 second, it automatically returns to the normal measuring mode. Note: It is always recommended to carry out a twopoint calibration for better accuracy. · For a two-point calibration, place the electrode in pH 7. 01 (or pH 6. 86) buffer. After the first calibration point has been accepted, the "pH 4. 01 USE" message appears. The message is held for 12 seconds, unless a valid buffer is recognized. If a valid buffer (pH 4. 01, pH 10. 01, or pH 9. 18) is detected, then the meter completes the calibration procedure. When the buffer is accepted, the LCD shows the accepted value with the "OK 2" message, and then the meter returns to the normal measuring mode. Note: When the calibration procedure is completed, the CAL tag is turned on. To quit calibration and to reset to the default values · After entering the calibration mode and before the first point is accepted, it is possible to quit the procedure and return to the last calibration data by pressing the /MODE button. The secondary LCD displays "ESC" for 1 second and the meter returns to the normal measuring mode. · To reset to the default values and clear a previous calibration, press the SET/HOLD button after entering the calibration mode and before the first point is accepted. [. . . ] HOLD appears on the secondary display and the reading will be frozen on the LCD (E. g. Release the button. BATTERY REPLACEMENT The meter displays the remaining battery percentage every time it is switched on. When the battery level is below 5%, the - + symbol on the bottom left of the LCD lights up to indicate a low battery condition. If the battery level is low enough to cause erroneous readings, the meter shows "0%" and the Battery Error Prevention System (BEPS) will automatically turn the meter off. [. . . ]