User manual EUTECH INSTRUMENTS ALPHA PH 200 REV 4

[. . . ] Instruction Manual lpha pH 200 1/8 DIN pH/ORP Controller Transmitter pH / mV / ºC 68X276101 | Rev. 4 | Feb 2008 PREFACE This manual serves to explain the use of the lpha pH 200 controller/transmitter. This manual functions in two ways: firstly as a step-by-step guide to help you operate the meter; secondly as a handy reference guide. This manual is written to cover as many anticipated applications of the lpha pH 200 controller/transmitter as possible. If there are doubts in the use of the lpha pH 200 controller/transmitter, do not hesitate to contact your nearest lpha Authorized Distributor. [. . . ] If this value is crossed, the set point relay 1 LED will light. Key in the password "022" as per procedure in Section 5. The screen will scroll P1. 1, SP1, then the current set point value. Press or keys and adjust first relay set point. You can adjust it in 0. 01 increments from 0. 00 to 14. 00 pH (-999 to 1000 mV). Press ENTER to confirm and continue to step three of P1. 2. P1. 2: Set relay as high or low set point Select a low set point to activate controller when your value undershoots the set point; select a high set point to activate controller when your value overshoots the set point. Using both SP1 and SP2, you can select lo/lo, lo/hi, hi/lo or hi/hi set points. Key in the password "022" as per procedure in Section 5. The screen will scroll P1. 2, SP1, and LOW (or HIGH). Press the or keys to toggle between LOW and HIGH. Press ENTER to confirm and continue to step 3 of P1. 3. - 17 - P1. 3: Set Hysteresis value Hysteresis prevents rapid contact switching if your value is fluctuating near the set point. Once activated, the relay will not return to resting position until the measured value has passed through the set point plus hysteresis value. Example: With a low set point of 4. 00 and a hysteresis value of 0. 5, the relay will activate at pH values below 4. 00, but will not de-activate till the measured pH value rises above pH 4. 50. The hysteresis window can be set to any value within the range shown below: · pH mode: 0. 00 to 2. 00 pH · ORP mode: 0 to 300 mV 1. Key in the password "022" as per procedure in Section 5. The screen will scroll P1. 3, HYS1, and current hysteresis value. Press the or keys to adjust the hysteresis value. Press ENTER to confirm and return to general Setup mode. Press and keys together (ESCAPE) to return to measurement mode. - 18 - 9. 4 Set Point 2 ­ P2. 0 Setup program P2. 0 allows you to set parameters for relay 2. P2. 1: select relay 2 set point value P2. 2: select relay 2 as low or high set point P2. 3: set relay 2 hysteresis value (dead band) Press and keys together (ESCAPE) at anytime, to leave the Setup mode and return to Measurement mode. P2. 1: Select relay set point value This lets you choose the pH (or ORP) value that will cause your controller to activate. If this value is crossed, the set point relay 2 LED will light. [. . . ] The electrical noise appears equally on the pH and reference electrodes, and is therefore rejected by the operational amplifier. - 31 - Appendix 2: Simple Explanation on the Function of Hysteresis SP1 Set to LO SP2 Set to HI RELAY ON RELAY OFF 4. 0 SP1 4. 5 7. 0 9. 5 10. 0 SP2 FORWARD DIRECTION REVERSE DIRECTION HYSTERESIS BAND (DEFAULT = 0. 5 pH) The controller relay activates when the set-point is reached. In the reverse direction, it does not deactivate when the value reaches the set-point. Instead, it continues to be active till the value reaches the amount set by the Hysteresis band. Appendix 3: Factory Defaults Resetting the controller to factory default settings (See program P6. 0) clears all calibration data and most other setup functions. The following settings will remain unchanged: 1. [. . . ]