1、 First, clarify two core requirements (must see, don't fall into pitfalls)
Determine the usage scenario (most critical)
Field/on-site inspection (such as fish ponds, rivers, and sewage treatment plant inspections): Choose products with long endurance, high waterproof rating (IP67 or above), strong anti-interference ability, and preferably equipped with handheld anti slip design to adapt to complex outdoor environments.
Laboratory routine testing: Priority should be given to high-precision, stable readings, compatible with reagent calibration, without excessive pursuit of waterproofing and battery life.
Emergency rapid detection: Choose the one that starts testing immediately, has a fast response time (≤ 30 seconds), and is easy to operate (one click reading), eliminating complex calibration steps.
Clear precision requirements (matching detection standards)
Conventional water quality screening (such as fish pond dissolved oxygen monitoring): accuracy ± 0.1mg/L is sufficient, meeting daily needs and offering high cost-effectiveness.
Research/compliance testing (such as environmental acceptance, laboratory analysis): selection accuracy ± 0.01mg/L, support for multi-point calibration, data traceability.
2、 3 key parameters (must see, not fooled)
Measurement range: Conventional range is 0-20mg/L (covering most scenarios of fresh water, sewage, and seawater), while special scenarios (such as high oxygen water bodies) range from 0-50mg/L.
Calibration method: Prioritize two-point calibration for players (simple and easy to operate, beginner friendly), support automatic calibration for peace of mind, and avoid frequent manual debugging errors.
Power supply method: For outdoor use, choose rechargeable lithium batteries (with a range of ≥ 8 hours). For laboratory use, it can be powered by both player charging and mains electricity to avoid sudden power outages affecting testing.
3、 2 practical additional features (on-demand selection, no waste of money)
(Universal): Equipped with a backlit display screen (readable in low light environments) and automatic data storage (convenient for subsequent export and organization).
Optional (on-demand): Equipped with automatic temperature compensation (to avoid water temperature affecting detection accuracy), Chinese interface (more convenient for beginners to operate), no need to pursue too many fancy functions (such as Bluetooth, printing, low cost-effectiveness).
4、 Last selection reminder (key to avoiding pitfalls)
Prioritize choosing legitimate brandsPortable dissolved oxygen analyzerSupport after-sales calibration and replacement of accessories (such as sensor probes, which are prone to wear and tear and need to be replaced regularly), to avoid buying niche brands and subsequent lack of after-sales and calibration services, which may cause the instrument to malfunction.