II. THE ENVIRONMENTAL MONITORING SYSTEM IN SHANGHAI
[ II-A | II-B | II-C | II-D | II-E | II-F ]
C. Quality control on monitoring data
Quality control measures are applied to the entire process of environmental monitoring in Shanghai, thus guaranteeing the reliability of all types of data. Such measures are classified as self-regulation and additional-control which are employed simultaneously.
The self-regulatory measures include:
- Complying with the Quality Control Diagram by randomly drawing 10-20 per cent of samples for parallel double-sample measurement and marked measurement of re-processing ratio.
- Adding certain quantities of standard samples or quality-controlled samples to every group of samples, randomly drawing 10-20 per cent of samples for parallel double-sample measurement and marked measurement of re-processing ratio.
- Employing 100 per cent parallel double-sample measurement, randomly drawing 10-20 per cent of samples for marked measurement of re-processing ratio.
One of the above three quality control measures must be applied to every environmental monitoring procedure. In key areas such as the upper reaches of the Huangpu River and its branches, the quality of basic variables such as nitrogen ammonia and CODMn are controlled by 100 per cent parallel double-sample measurement.
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