User manual EUTECH INSTRUMENTS CYBERSCAN DO 100 DISSOLVED OXYGEN METER

[. . . ] Instruction Manual DO 100 Hand-held Dissolved Oxygen Meter 68X235201 Technology Made Easy . . . rev 4 01/04 Preface This manual serves to explain the use of the DO 100 hand-held meter. It functions as a step by step guide to help you to operate the meter and as a handy reference guide. It is written to cover as many anticipated applications of the DO 100 meter as possible. If there are doubts in the use of this meter, please do not hesitate to contact the nearest Eutech Instruments/Oakton Instruments Authorised Distributor. [. . . ] Once you come to the [SAL, P 2. 1] menu shown in Figure 26, press ENTER. Use MI/ or MR/ key to set the Salinity value in ppt of the liquid where DO is being measured. NOTE: Press HOLD key to skip this operation and move on to the next menu, or press CAL/MEAS key to exit setup menu to go back to measurement mode. 8. 2. 3 P 2. 2: bAr Figure 26: Adjusting for Salinity Value This menu allows: · · Selecting the prefered unit of pressure--either mm Hg or kPA. Keying of actual atmospheric pressure value based on the altitude of the location. This is an important feature as DO is dependent on pressure (refer Section 12. 1 on page 48). Without you having to refer to tables, the DO 100 will use this input to compensate for the measured value automatically. Once you come to the [bAr P 2. 2] menu shown in Figure 27, press ENTER. Press MI/ or MR/ key to select "Hg" or "PA" as unit of pressure measurement. Press ENTER key to go into the next level. NOTE: The range for atmospheric correction ranges from 555 to 808 mm Hg or 74 to 108 kPA. or MR/ key to adjust value accordingly to the location's actual atmospheric 5. The meter will accept the value and move on to the next menu. Figure 27 on the following page shows the flow diagram on this menu. 33 Instruction Manual DO 100 NOTE: Press HOLD key to skip any part of the operation and move on to the next menu, or press CAL/MEAS key to exit setup menu to go back to measurement mode. Figure 27: Select Units for Pressure and Adjust Its Value 34 Instruction Manual DO 100 REMARKS: The following 2 menus display the condition of the DO probe from the last calibration performed. 3. P 3. 0: EL 1 This menu displays the slope of probe as a ratio of ideal to its measured value. Once you come to the [EL 1, P 3. 0] menu shown in Figure 28, press ENTER. 3. P 3. 2: EL 3 This menu displays the actual offset value in mV for its last zero point calibration. Once you come to the [EL 3, P 3. 2] menu shown in Figure 28, press ENTER. Press ENTER or MODE key to go into the next menu. Figure 28: Checking Electrode Status 35 Instruction Manual DO 100 8. 2. 6 P 4. 0: do This menu allows you to choose between mg/L or ppm as unit of measurement. Press MI/ or MR/ key to select "mg/L" or "ppm" as unit of measurement. See Figure 29. Figure 29: Selecting mg/L or ppm as units of measure 8. 2. 7 P 4. 1: rdY You can activate or deactivate the READY (rdY) stabilising feature in the meter in this menu. Once you come to the [rdY, P 4. 1] menu shown in Figure 30, press ENTER. or MR/ key to toggle between ON or Figure 30: READY 36 Instruction Manual DO 100 8. 2. 8 P 4. 2: A. oFF The meter has a Power Auto-off feature that switches off the unit 20 minutes after the last key press. In situation where longer period of time is needed to take measurement, the power Autooff feature can be switched off in this menu. Once the [A. oFF P 4. 2] menu is reached (see Figure 31), press MI/ OFF). NOTE: Press HOLD key to skip any part of the operation and move on to the next menu, or press CAL/MEAS key to exit setup menu to go back to measurement mode. Figure 31: Auto-Off or MR/ key to turn Auto-off feature ON (or 8. 2. 9 P 5. 0: r. Set This allows you to clear all parameters programmed above and re-set it to factory default values. Once the [r. Set, P 5. 0] menu is reached (see Figure 32), press MI/ or MR/ key to turn reset feature ON (or OFF). [. . . ] There is an optimum DO level for this process and if DO level falls too low, the micro-organisms die and the decomposition ceases. If DO level is too high, more power is used than necessary for aeration and the process becomes costly. In boiler water application, presence of oxygen in the water will increase corrosion and helps build up boiler scale that inhibits heat transfer. In such instance it is critical to keep DO concentration to a minimum. [. . . ]