If you plan to supply water quality monitoring instruments to the domestic market or install them on public monitoring networks, obtaining type approval is effectively a precondition. Type approval is a system by which the state verifies and registers, in advance, whether a specific model meets statutory performance criteria. Instruments without it cannot be used for official test reports or regulatory compliance. This guide walks manufacturers, importers and operators through the steps from application to registration, from a practical standpoint.
1. Legal Basis of Type Approval
Type approval for water quality monitoring instruments rests on the Act on the Environmental Testing and Inspection and its subordinate notices. At its core is assuring the reliability that measurement data needs in order to carry legal effect. Type approval is therefore not a mere quality certification: it is the institutional mechanism that lets measured values serve as the basis for administrative actions such as effluent charges and compliance determinations.
2. Scope of Covered Instruments
Covered instruments are designated by parameter. Representative examples include:
- pH, chemical oxygen demand (COD), total organic carbon (TOC)
- Suspended solids (SS)/turbidity, total nitrogen (T-N)/total phosphorus (T-P)
- Dissolved oxygen (DO), electrical conductivity, water temperature and other auxiliary parameters
Even for the same measuring principle, a different model, measuring range or detection method requires separate approval. The first step before applying is to organise your product line-up by parameter and model to fix the approval units.
3. Application Documents and Performance Test Items
Documents typically required at application are as follows.
- Application form and instrument specification (measuring principle, range, resolution)
- Structural and circuit diagrams, software version information
- In-house performance test results and calibration procedures
Performance testing evaluates repeatability, linearity, response time, zero/span drift and interference effects against prescribed reference values. Stability under field conditions (temperature swings, sample matrix) is decisive, so prepare verification data that reflects real operating conditions rather than laboratory data alone.
4. Review Procedure and Timeline
The general flow is: ① application intake → ② document conformity review → ③ performance testing (test laboratory) → ④ result review → ⑤ approval and registration. Timelines vary widely with the parameter, test load and whether supplementation is requested; repeated supplementation requests can extend the process considerably, so the completeness of the initial submission governs the overall lead time. Test scheduling depends on the laboratory's queue, so early booking is advantageous.
5. Validity, Changes and Re-approval
Type approval is not indefinite; a validity period and renewal requirements apply. Even after approval, a substantive change to the measuring principle, core components or firmware requires a change approval or re-approval. Treating such a change as a "minor update" and omitting notification can jeopardise the validity of the approval, so it is safest to link your design-change management procedure to the type-approval status.
6. Practical Checklist
- Approval units (parameter, model, measuring range) fixed
- Submission completeness — specification, structural diagram and SW version aligned
- In-house pre-verification against reference values completed for each test item
- Test-laboratory schedule booked and sample/installation conditions prepared
- Change-management procedure linked to type-approval status
Need Help?
Sechang has experience supporting type approval in the field of water and environmental monitoring instruments. If you need consultation across the whole type-approval process — selecting target parameters, preparing for performance testing, checking submission completeness — please reach out below.
▶ Contact Sechang about type approval and monitoring instruments