[. . . ] If service is required, contact the dealer from whom you purchased the instrument. If under warranty, report the model number, date of purchase, serial number and the nature of the failure. 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. [. . . ] The glass bulb at the end of the electrode is sensitive to electrostatic discharges. During operation, ESD wrist straps should be worn to avoid possible damage to the electrode by electrostatic discharges. Any variation introduced by the user to the supplied equipment may degrade the instrument's EMC performance. To avoid electrical shock, do not use this instrument when voltages at the measurement surface exceed 24 VAC or 60 VDC. To avoid damages or burns, do not perform any measurement in microwave ovens. ISTR98129R2 01/02 OPERATIONAL GUIDE To turn the meter on and to check battery status Press and hold the MODE button for 2-3 seconds. All the used segments on the LCD will be visible for a few seconds, followed by a percent indication of the remaining battery life. To change the temperature unit To change the temperature unit (from °C to °F), from measurement mode, press and hold the MODE button until TEMP and the current temperature unit are displayed on the lower LCD. Use the SET/HOLD button to change the temperature unit, and then press MODE button twice to return to normal measurement mode. To freeze the display Press the SET/HOLD button for 2-3 seconds until HOLD appears on the secondary display. To turn the meter off Press the MODE button while in normal measurement mode. Notes: Notes · Before taking any measurement make sure the meter has been calibrated. · To clear a previous calibration, press the MODE button after entering the calibration mode. The lower LCD will display ESC for 1 second and the meter will return to normal measurement mode. · 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. bration) or pH 6. 86 BUFF (for NIST 4. 01/6. 86/9. 18 calibration). Calibration procedure From measurement mode, press and hold the MODE button until CAL is displayed on the lower LCD. The LCD will display pH 7. 01 USE or pH 6. 86 USE (if you have selected the NIST buffer set). · For a single-point pH calibration, place the electrode in any buffer from the selected buffer set (eg. If using pH 4. 01 or pH 10. 01, the meter will display OK for 1 second and then return to measurement mode. If using pH 7. 01, after recognition of the buffer the meter will ask for pH 4. 01 as second calibration point. Press the MODE button to return to measurement mode or, if desired, proceed with the 2-point calibration as explained below. Note: Note It is always recommended to carry out a twopoint calibration for better accuracy. [. . . ] 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 however the battery level is so low as to cause erroneous reading, the Battery Error Prevention System (BEPS) will automatically turn the meter off. To change the batteries, remove the 4 screws located on the top of the meter. pH ELECTRODE MAINTENANCE · When not in use, rinse the electrode with water to minimize contamination and store it with a few drops of storage (HI 70300) or pH 7 (HI 7007) solution in the protective cap after use. · If the electrode has been left dry, soak in a storage or pH 7 solution for at least one hour to reactivate it. [. . . ]