DOG-209F ppm Dissolved Oxygen Electrode
Instruction
Application of dissolved oxygen sensor range:
DOG-209F dissolved oxygen sensor has high stability and reliability, can be used in harsh environments, small amount of maintenance, continuous determination of dissolved oxygen is applicable to the field of city sewage treatment, industrial waste water treatment, aquaculture and environmental monitoring.
1. The technical indexes of DOG-209F Dissolved oxygen electrode are as follows:
| Dimension data | The measuring principle | Film type current sensor (polarographic electrode) | |
| | Breathable film thickness | 50μm | |
| | Electrode shell material | UPVC or stainless steel | |
| | Temperature compensation resistor | PT1000;PT100;10K; 30K 2.252 etc. | |
| | Sensor life | >2 years | |
| | Cable length | 5m(SFTP) | |
| | | | |
| The performance of sensor | The detection limit | 0.01mg/l(20 ºC) | |
| | Measurement limit | 20mg/l | |
| | Response time | 3min(90%,20 ºC ) | |
| | Polarization time | 1h | |
| | The minimum flow rate | 2.5cm/s | |
| | Drift | <2%/month | |
| | Measurement error | <±0.1mg/l | |
| | Output current | 20-25nA/0.1mg/l | Note:The largest current is 3.5uA. |
| | Polarization voltage | 0.7V | |
| | Zero oxygen | <0.1mg/l(5min) | |
| | The calibration interval | >60 days | |
| The use of temperature | The water quality tested | 0-80 ºC | |
| | | | |
The electrode shape
(1) the electrode in the vertical position, unscrew the electrode protective sleeve
(2) electrode film head screw
(3) rinse the electrode core and using tissue dry electrode with distilled water, after a period of use, such as found in the electrode core Silver Ring
Black, can be more than 1000 mesh fine sandpaper to Polish
the electrolyte into the film head part of new (about 2/3 by volume), carefully put the film head part is screwed into the electrode inner core,
Precision of the "two back into the method" and gradually make the film gradually close to the gold electrode surface. Please note that the screw electrode film head parts: should slowly tighten, prevent excess electrolyte membrane head component can not be exhausted in time and make the film up the gold electrode surface and even the film breaking; may also affect the response time of the sensor and the zero oxygen values.
(5) at each change of membrane or change of electrolyte, electrode should be re polarization and calibration.
(6) polarization of electrode: electrode is connected to the instrument, continuous electricity for 2 hours or more, is the polarization, polarization of electrode to Calibration.
Wiring of dissolved oxygen electrode:
The specific connection please see the table:
| No. | Color | | Connection point |
| 1 | White | Temperature | Connect meter's temperature compensation TEMP |
| 2 | Black | Temperature | Connect meter's temperature compensation TEMP |
| 3 | Yellow | The anode electrode | Connect meter's anode DO- |
| 4 | The white inner core | The cathode electrode | Connect meter's cathode DO+ |
| 5 | Blue | external shield | Connect meter's grounding GND |
3. The maintenance of electrode:
The measurement value is correct or not, have a great relationship, and the measuring electrode and therefore, in the whole measurement system, maintain the measuring electrode is the key.
(1) As found in the measurement system of long response time, rupture of membranes, anaerobic medium current increases and so on, it needs to be replaced, the replacement of the electrolyte membrane maintenance work. Replacement of membrane, electrolyte maintenance once every six months, each change of membrane or change of electrolyte, electrode should be re polarization and calibration.
(2) For treating gold cathode
Oxygen electrode is used for a period of time, the cathode surface such as gold small brown, must remove the film frame, distilled water after the dry cleaning with more than 005 metallographic sandpaper gently friction golden surface, polishing processing. After polishing, rinsed with distilled water clean install the film frame.
Surface cleaning electrode film: anti pollution Teflon membrane such as contaminated, can use gauze with a small amount of diluted detergent gently washing, or installation of spray water cleaning device, automatic timing on dissolved oxygen measuring electrode membrane surface cleaning.
