EIT LiQlyzer DO Dissolve Oxygen Meter
The amount of oxygen dissolved in water is referred to as dissolved oxygen.
It is necessary for fish and other aquatic species to survive.
How we measure DO
Optical DO Sensor
The interaction between oxygen and certain luminous dyes is measured using optical dissolved oxygen sensors. These dyes become excited when exposed to blue light and produce light as the electrons return to their usual energy level. Because oxygen molecules interact with the dye when dissolved oxygen is present, the wavelengths returned are limited or altered. The effect is inversely proportional to the partial pressure of oxygen in the atmosphere.
Polarographic DO Sensor
A polarographic DO sensor is an electrochemical sensor that comprises of a potassium chloride solution with a silver anode and a noble metal cathode. Before calibrating or measuring, the instrument must be turned on for a 5-60 minute warm-up period to polarise the electrodes. The electrical current recorded by the polarographic DO sensor increases when more oxygen travels through the membrane and is lowered.
Galvanic DO Sensor
Galvanic DO sensors have an electrochemical reaction that is very similar to polarographic DO sensors, but without the necessity for a separate, continuous voltage. The electrons flow internally from the anode to the cathode as the dissimilar electrodes self-polarize. The cathode stays inert, merely transmitting electrons and without interfering with the reaction. As a result, the anode is oxidised, and oxygen is reduced at the cathode's surface.
How we choose DO meter & Sensor
1. Understand your application & process range
2. Accuracy
3. Output signal
4. Number of relays
5. Power supply
6. IP rating
7. Pressure rating
8. Medium temperature range
9. Cable length
 LQDO-T30AC |
 LQDO-T40AC |
 LQDO-T60AC |
| Range: 0-20mg/L / 0-100μg/L | ||
| Communication: 4-20mA RS485 ModbusRTU | ||
| Working Condition: 0-60°C | ||
| Power Supply: 240VAC | ||
| Installation: Panel/ Wall mounted/ Pipeline | ||
| Model | LQDO-T30AC/T40AC | LQDO-T60AC |
| Accuracy | ±3%FS | ±1%FS |
| Relay control contacts | 3A 250VAC, 3A 30VDC | 5A 240VAC, 5A 28VDC, 120VAC |
| Protection | IP54 | IP65 |
| Dimension | 96*96*135(mm) | 144*144*107(mm) |
| Hole Size | 92.5*92.5(mm) | 138*138(mm) |
| Other Functions | - | Data record &Curve display |
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| Model | SDO4773 | SDO4571-VP-KA12 | SDO4760D | SDO4800 |
| Measuring Method | Polarography | Polarography | Optical | Polarography |
| Housing Material | POM + Stainless steel | SS316L | POM+ 316 Stainless steel | SS316L |
| Measuring Range | 0-20mg/L | (0~20.0)mg/L, 0~100ug/L | 0-20mg/L | 0-20mg/L |
| Accuracy | ±5%F.S | ±1%F.S | ±3%F.S | ±1%F.S |
| Pressure Range | ≤0.3Mpa | |||
| Temperature Compensation | PT1000 | |||
| Temperature Range | 0-50℃ | 0-130℃ | 0-50℃ | 0-80℃ |
| Installation Thread | Upper NPT3/4’’,1’’ | VP | G3/4 End thread | Compaction Style |
| Application | General application, river, lake,drink water, environment protection ,etc | Pharmaceutical, biotech, beer, Fermentation, sterilization, autoclaving, CIP etc | General application, river, lake, drink water, environmental protection, etc | Power plant, boiler water, etc |
| Cable Length | Standard 10m cable, can be extended | |||