Water quality. Performance requirements and conformity test procedures for water monitoring equipment. Automatic sampling devices (samplers) for water and waste water
1Key Takeaways
1 Scope This document specifies general requirements, performance requirements and conformity test procedures for automatic sampling devices (samplers) for water and waste water that: — sample water and waste water from non-pressurized (i.e. open to atmosphere…
2Expert Interpretation
BS EN 16479:2023 specifies the performance requirements and compliance testing procedures for automatic water sampling equipment, covering key indicators such as sample volume, sampling principle, pipeline speed, power supply, sample integrity, timing error, and the influence of ambient temperature. It is applicable to water and wastewater sampling to ensure the representativeness of the samples.
Standard Overview
BS EN 16479:2023 is the British adoption version of the European standard EN 16479, published in April 2023, replacing the 2014 version. This standard provides uniform performance requirements and compliance test procedures for **automatic samplers**, applicable to the collection of water and wastewater samples from non-pressured (i.e., open atmosphere) channels or containers, supporting discrete or mixed sampling triggered by time, flow rate, or event. The standard does not cover online analyzers with built-in sampling systems and does not cover installation and continuous use. Its development stems from the stringent requirements of European and national regulations for water quality monitoring, aiming to ensure the reliability and representativeness of sampling equipment, and is a key technical specification in the field of water environment monitoring.
Main Performance Requirements
Standard 5.1 to 5.7 specify the core performance indicators, including sample volume deviation and repeatability, sampling principle error, pipeline flow rate, power supply adaptability, sample integrity, timing error, and the influence of ambient temperature.
The following table summarizes the key requirements:| Performance Items | Requirements | Test Methods |
|---|---|---|
| Sample Volume Deviation | ≤5% | 6.4.1 Volume Test|
| Volume Repeatability | Set volume >100ml: ≤2.5%; ≤100ml: ≤4.0% | 6.4.1 Calculate Coefficient of Variation |
| Sampling Principle Timing Error | ≤1% | Sampling interval; event trigger ≤ 10s6.4.2 Principle Test |
| Sampling pipeline flow rate | Average value ≥ 0.5m/s (all test lifts) | 6.4.3 Flow rate test |
| Power adaptability | Flow rate still ≥ 0.5m/s at all rated voltages | 6.4.4 Power Supply Test |
| Sample Integrity | No significant difference in BOD/COD/Total Nitrogen/Total Phosphorus (ANOVA) | 6.4.5 Analysis of Variance |
| Timing Error | ≤±10s/24h | 6.4.6 Timed Testing |
| Ambient Temperature Influence | Volume Deviation and Repeatability Still Meet Requirements 5.1 | 6.4.7 Temperature Test |
Among them, the sample integrity test requires the use of wastewater from urban sewage treatment plants (BOD 12.5-37.5 mg/L, COD 62-187 mg/L, total nitrogen 7.5-22.5 mg/L, total phosphorus 1.0-3.0 mg/L), by comparing
Explanation of Technical Terms
The standard defines several sampling modes: **CTCV (Constant Time Constant Volume)**, which collects an equal volume of samples at fixed intervals; **CVVT (Constant Volume Variable Time)**, which collects equal volumes of samples at varying frequencies with the flow rate; and **CTVV (Constant Time Variable Volume)**, which collects samples at fixed intervals at varying volumes with the flow rate. Event-triggered sampling is also available. These modes are illustrated in Figure 1 and are suitable for different monitoring needs.
Lift height refers to the vertical distance from the water surface to the sampler inlet. The maximum rated lift is declared by the manufacturer.
The **sample linear velocity** requirement of ≥0.5 m/s is to prevent suspended solids settling and avoid clogging, and to ensure representativeness when matched with the pipeline inner diameter (≥9 mm).
Application Case
Taking an urban wastewater treatment plant as an example, an **automatic sampler** is used to monitor effluent quality. A sample integrity test must be performed according to standards: 24 discrete samples (one every 60 minutes) are collected at the rated maximum lift and half lift, mixed, and then tested for BOD, COD, total nitrogen, and total phosphorus. Simultaneously, an equal amount of samples are manually collected for ANOVA analysis. If the result is satisfactory (F < Fcrit), the sampler can be used for compliant monitoring of wastewater treatment plants. In practice, as shown in Example B.7, when the F-value of the treatment factor (automatic vs. manual) reaches 14.4 (>7.71), it indicates that the sampler has altered the sample and needs adjustment or replacement.
Background and Technological Evolution of Standard Development
EN 16479 was first published in 2014, driven by the European Water Framework Directive (2000/60/EC) and the Municipal Wastewater Treatment Directive (91/271/EEC). The main updates in the 2023 edition include: stricter requirements for sample volume repeatability (categorized by volume), refined event trigger response time (≤10s), improved environmental temperature testing (differentiating between temperature control and non-temperature control), and increased standardization of statistical methods (such as ANOVA). Technically, Annex C of the 2023 edition provides more specific ranges of wastewater components and incorporates a reference to ISO 5667-10:2020, reflecting alignment with international standards. Furthermore, the power supply testing method for battery-powered samplers has been revised, requiring testing until a low battery alarm is triggered.
Implementation Recommendations
For users and manufacturers, the following recommendations are made: 1) Select the appropriate lift and set volume according to the actual application, and calibrate regularly; 2) Pay attention to the ambient temperature range. For outdoor use, select a model with antifreeze function (temperature range 0°C to +40°C or -10°C to +40°C); 3) When conducting sample integrity tests, ensure that the test water composition complies with the requirements of Appendix C; 4) Follow the manufacturer's maintenance instructions and avoid adjusting the equipment during testing; 5) Record and report all test data using the report template in Appendix D. When using an **automatic sampler**, it is also necessary to refer to the sampling guidelines of ISO 5667-10 to ensure that installation and operation are compliant.