User manual HANNA INSTRUMENTS HI 23

[. . . ] HI 23 / HI 24 Series Wall-mounted, Microprocessor-based, Conductivity and TDS Process Controllers Instruction Manual 1 Dear Customer, Thank you for choosing a Hanna Product. This instruction manual refers to the following products: HI 23211 HI 23212 HI 23221 HI 23222 EC controller with dual setpoint, ON/OFF control and analog output EC controller with dual setpoint, ON/OFF control and RS 485 port EC controller with dual setpoint, ON/OFF and PID control, and analog output EC controller with dual setpoint, ON/OFF and PID control, and RS 485 port EC and TDS controller with dual setpoint, ON/OFF control and analog output EC and TDS controller with dual setpoint, ON/OFF control and RS 485 output EC and TDS controller with dual setpoint, ON/OFF and PID control, and analog output EC and TDS controller with dual setpoint, ON/OFF and PID control, and RS 485 port HI 24211 HI 24212 HI 24221 HI 24222 Please read this instruction manual carefully before using the instrument. It will provide you with the necessary information for the correct use of the instrument, as well as a precise idea of its versatility. These instruments are in compliance with the directives. © 2001 Hanna Instruments All rights are reserved. [. . . ] For greatest accuracy, it is recommended that the instrument is calibrated frequently. Before beginning normal operation, it is recommended to standardize the probe with the Hanna calibration solution close to the expected sample value and inside the selected range. EC AND TDS CALIBRATION The calibration points for EC and TDS are as follows: Range Calibration point(s) 0. 0÷199. 9 µS/cm 84. 0 µS/cm 0÷1999 µS/cm 1413 µS/cm 0. 00÷19. 99 mS/cm 5. 00 - 12. 88 mS/cm 0. 0÷199. 9 mS/cm 80. 0 - 111. 8 mS/cm 0. 0÷100. 0 ppm 42. 0 ppm 0÷1000 ppm 800 ppm 0. 00÷10. 00 ppt 6. 44 ppt 0. 0÷100. 0 ppt 55. 9 ppt The user should select the appropriate range to calibrate (setup code 03). The temperature probe should also be connected to the process meter (when using a different temperature probe). The user is also guided with indications on the display during the calibration procedure. Initial Preparation Pour a small quantity of the calibration solution (e. g. For accurate calibration use two beakers containing the same solution, the first one for rinsing the probe, the second one for calibration. 32 To obtain accurate readings, use the calibration solution in the selected range and closer to the values to be measured. Offset Calibration · To perform the EC or TDS calibration enter the calibration mode, by pressing CAL and entering the password. · After the correct password is entered, the control actions stop and the primary LCD will display the first EC or TDS calibration value, with the "CAL" indicator blinking. The secondary LCD displays the temperature. Note If the wrong password is entered the system reverts back to normal operation, displaying EC or TDS values. · 0 is the default value for the 1st calibration point. · Only when the reading is stable the "CAL" indicator will stop flashing (after about 30 seconds) and the "CFM" indicator will start blinking. · Press CFM to confirm the calibration point; the primary LCD will display the second expected buffer value. If the zero calibration cannot be performed, "ERROR" will blink. Cell constant calibration · Select the solution value on the primary display by pressing or if the selected range has two possibilities (e. g. · Immerse the EC/TDS probe with the temperature sensor in the selected solution. The level of solution must be higher than the holes of the EC/TDS probe sleeve. Tap the EC/ TDS probe repeatedly on the bottom of the beaker and stir to ensure that no air bubbles are trapped inside the sleeve. 33 · When the reading is stable, "CAL" will stop flashing (after about 30 seconds) and "CFM" indicator will blink. · Press CFM to confirm the calibration point; if the reading is close to the selected solution, the meter stores the reading. If the reading is not close to the selected solution, "ERROR" will blink. A 2-point calibration is always suggested. To calibrate offset only, just press CAL after confirmation (with CFM) of the zero reading; the meter will return to normal operational mode. [. . . ] When the last calibration data is required, the "no CAL" message is displayed if no calibration procedure was performed. Unlike EC/TDS calibration, the user has no information on calibration need for other ranges, other than the awareness that EEPROM was reset. After an EEPROM reset, all calibrations (input and output) have to be performed in order to obtain correct measurements. 53 EC VALUES AT VARIOUS TEMPERATURES Temperature has a significant effect on conductivity. Table below shows EC values at various temperatures for the Hanna calibration solutions. [. . . ]