How long to monitor

Guidance on the number of readings, based on these factors, is provided in Table 5.3 (see colour section). In addition the variation of results and any anomalies will influence whether more than the suggested number of readings are required. It should be noted that the suggested periods and frequency of monitoring in Table 5.3 are unlikely to be applicable to monitoring in or around Part 2A sites. 

It is important to consider the benefits of collecting any extra data and whether or not any useful purpose will be served. Groxmd gas investigations are usually intended to provide robust data for the design of protection. They are not normally designed as an academic or research exercise. 

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