Polarographic vs Optical Dissolved Oxygen Meter Qiwei JPB-70A Malaysia
Polarographic vs Optical Dissolved Oxygen Meter Qiwei JPB-70A Malaysia
Portable dissolved oxygen meters generally use either an electrochemical membrane sensor or an optical sensor. Both technologies can measure oxygen in water, but their purchase price, maintenance requirements and operating methods are different.
The Qiwei JPB-70A uses a polarographic membrane-type dissolved oxygen electrode. It provides an economical solution for routine measurements in fish ponds, aquaculture farms and wastewater aeration tanks.
Polarographic versus Optical DO Meter
FeaturePolarographic DO MeterOptical DO MeterExampleQiwei JPB-70AHigher-specification optical modelMeasurement principleElectrochemical reactionLuminescence-based sensingMembrane and electrolyteRequiredNormally no liquid electrolyteWater movement during testingRequiredLess dependent on flowPreparation timeUsually requiredUsually shorterRoutine maintenanceMore frequentLowerSensor-cap replacementNot applicable in the same formRequired periodicallyInitial purchase priceGenerally lowerGenerally higherRoutine aquaculture checksSuitableSuitableLow-maintenance field useAcceptable with proper careOften more convenient
The best choice depends on the user’s budget, measurement frequency and willingness to maintain the sensor.
How Does the JPB-70A Electrode Work?
The JPB-70A uses a polarographic dissolved oxygen electrode containing:
An oxygen-permeable membrane
Internal electrolyte
Electrochemical sensing components
A temperature sensor
Oxygen passes through the membrane and produces an electrical signal related to the dissolved oxygen concentration.
Because the sensor consumes a small amount of oxygen during measurement, water must move gently across the membrane.
Advantages of the JPB-70A Polarographic Sensor
Lower Initial Investment
Polarographic meters are generally more affordable than optical DO instruments. This makes the JPB-70A suitable for customers who are starting routine dissolved oxygen monitoring.
Replaceable Consumables
The membrane and electrolyte can be serviced when the sensor response becomes slow or unstable.
Suitable for Common Field Applications
The JPB-70A can be used for:
Fish ponds
Shrimp farms
Hatcheries
Koi ponds
Wastewater aeration tanks
Rivers and lakes
Agricultural water systems
General field inspections
Straightforward Readings
The instrument displays dissolved oxygen and temperature without requiring complicated data-management functions.
Limitations of a Polarographic DO Meter
Users should understand the operating requirements:
The electrode requires preparation before measurement
Gentle water movement is necessary
The membrane can be damaged
Electrolyte requires periodic attention
Air bubbles beneath the membrane can cause problems
Contamination may slow the response
Regular calibration is important
These are normal characteristics of the sensor technology and do not necessarily indicate an instrument fault.
Advantages of an Optical DO Meter
Optical dissolved oxygen sensors are commonly selected when the user wants:
Lower routine maintenance
Less dependence on water movement
Faster field operation
Better suitability for low-flow samples
No liquid electrolyte replacement
Advanced data logging
Higher-end environmental or laboratory functions
However, optical sensors usually have a higher initial cost, and their sensing caps are consumable components that eventually require replacement.
Which Technology Is Better for Aquaculture?
For routine fish-pond measurements, both technologies can be suitable.
Choose the Qiwei JPB-70A polarographic meter when:
Budget is important
Measurements are taken manually
Staff can perform basic probe maintenance
A 0.1 mg/L resolution is sufficient
The meter is used for routine operational checks
Consider an optical DO meter when:
The instrument is used very frequently
Minimum sensor maintenance is preferred
Measurements are taken in low-flow water
Advanced data functions are required
The higher purchase price is acceptable
Is Optical Always More Accurate?
No. Sensor technology alone does not determine overall accuracy.
Consider:
The manufacturer’s stated accuracy
Calibration quality
Temperature compensation
Salinity and pressure compensation
Sensor condition
Measurement technique
Sample conditions
Maintenance history
A well-maintained polarographic meter may provide more useful results than a poorly maintained optical instrument.
JPB-70A Main Specifications
Dissolved oxygen range: 0.019.9 mg/L
Resolution: 0.1 mg/L
Basic DO accuracy: approximately ±0.3 mg/L
Temperature range: 040°C
Automatic temperature compensation
Polarographic membrane-type DO electrode
Portable field configuration
These specifications make the JPB-70A appropriate for general aquaculture and wastewater spot checks.
Maintenance Required for the JPB-70A
To maintain consistent performance:
Inspect the membrane before use
Check for trapped air bubbles
Maintain the correct electrolyte level
Keep water moving across the membrane
Calibrate periodically
Rinse the probe after every test
Clean off algae and wastewater residue
Replace damaged membrane components
Store the electrode correctly
Users should keep spare membrane parts and the correct electrode solution available.
Choose According to the Application
Before purchasing, answer these questions:
How frequently will the meter be used?
What measurement accuracy is required?
Is the water moving or stationary?
Can staff perform basic electrode maintenance?
Is data logging required?
Is the sample freshwater or saline?
Is the test for routine control or formal reporting?
What is the available budget?
For many farms and general wastewater facilities, the JPB-70A offers a practical entry point into dissolved oxygen monitoring.
Buy Qiwei JPB-70A in Malaysia
The Qiwei JPB-70A Polarographic Dissolved Oxygen Meter is available from MTM Precision in Malaysia.
Contact us for stock, pricing, accessories and assistance comparing polarographic, optical, portable and online dissolved oxygen meters.
We serve customers throughout Selangor, Kuala Lumpur, Johor, Penang, Melaka, Negeri Sembilan, Perak, Pahang, Kelantan, Terengganu, Kedah, Perlis, Sabah and Sarawak.
Contact MTM Precision
MTM Precision Sdn. Bhd. (744811-A)
Telephone: +603-8080 7172
WhatsApp: +6016-660 7346
Email: mtmpre@yahoo.com / enquiry@mtmpre.com.my
Website: www.mtmpre.com.my
Showroom & Service Centre
No. 29-1 & 29-2, Jalan Bandar 18,
Pusat Bandar Puchong,
47160 Puchong, Selangor, Malaysia.
Contact MTM Precision to compare the Qiwei JPB-70A with optical dissolved oxygen meters in Malaysia.
18 Sep 2026
