User manual HANNA INSTRUMENTS HI 251

[. . . ] Instruction Manual Microprocessor-Based pH/mV/ºC Bench Meters HI 250 HI 251 w w w. c o m 1 Dear Customer, Thank you for choosing a Hanna Instruments product. Please read this instruction manual carefully before using the instruments. This manual will provide you with the necessary information for correct use of the instruments, as well as a precise idea of their versatility. [. . . ] Press CAL to escape without saving. SERIAL COMMUNICATION COMMAND PREFIX SET Press CAL when the command prefix is displayed. The command prefix (0 to 47) will start blinking. Press the ARROWkeys to change the command prefix. Press CFM to save the modified command prefix value. Note: See the PC interface section on page 25 for a complete explanation. The command prefix must be 16 if HI 92000 PC software is used. Press CAL when the calibration time-out is displayed. Calibration time-out (OFF or 1 to 7 days) will start blinking. CAL INTV CALIBRATION ALARM TIME-OUT SET Press the ARROWkeys to change the calibration time-out value. Press CFM to save the modified calibration time-out value. Press CAL to escape without saving. 20 Press CAL when the instrument ID is displayed. The instrument ID (0000 to 9999) will start blinking. INSTRUMENT ID PARAMETER SET Press the ARROWkeys to change the instrument ID value. Press CFM to save the modified instrument ID value. Note: The instrument ID is downloaded to a PC as part of a logged data, set to identify its origin. 21 TEMPERATURE CALIBRATION (for technical personnel only) All the instruments are factory calibrated for temperature. Hannas temperature probes are interchangeable and no temperature calibration is needed when they are replaced. If the temperature measurements are inaccurate, temperature recalibration should be performed. For an accurate recalibration, contact your dealer or the nearest Hanna Customer Service Center, or follow the instructions bellow. Prepare a vessel containing ice and water and another one containing hot water (at a temperature of around 50 ºC). Place insulation material around the vessels to minimize temperature changes. Use a calibrated thermometer with a resolution of 0. 1 ºC as a reference thermometer. With the instruments off, press and hold down the CAL&LOG keys, then power on the instruments. The CAL tag will appear and the secondary LCD will show 0. 0 ºC. CAL C Immerse the temperature probe in the vessel with ice and water as near as possible to the reference thermometer. Allow a few seconds for the probe to stabilize. Use the ARROW keys to set the reading on the secondary LCD to that of ice and water, measured by the reference thermometer. [. . . ] Use: general purpose. 12 mm 0. 5" "S" VERSION HI 2020 HI 1332 120 mm 4. 7" "S" VERSION 35 HI 1312 FC 100B Plastic-body (Kynar®), double junction, refillable, combination pH electrode. Use: general purpose for food industry. 12 mm 0. 5" FC 100 120 mm 4. 7" FC 200B Plastic-body (Kynar®), open junction, conic, Viscolene, non-refillable, combination pH electrode. Use: meat & cheese. 6 mm 0. 25" FC 200 75 mm 2. 95" FC 210B Glass-body, double junction, conic, Viscolene, non-refillable, combination pH electrode. Use: milk, yogurt. 12 mm 0. 5" FC 210 120 mm 4. 7" FC 220B Glass-body, triple-ceramic, single junction, refillable, combination pH electrode. [. . . ]