Grab samples and sample table

[wastewater_belgium]

Hello,

In case of grab sample should collPer be left empty?

In case of 2 or more grab samples done at the same site throughout the day and then pooled by the technician before sending to the laboratory. Each grab sample should be reported separately in sample table. The final pooled sample should also be reported. For this final sample is it correct if collDT stays empty and collDTtart and collDTEnd are completed respectively with the collection datetime of the earliest grab sample and collection datetime of the latest grab sample?
Also for the final grab sample what collType should be reported? Manual composite sample? Manual composite sample (as well as Passive Sample - General and I think a Flow proportional sample option should be added too) is not descibed in the documentation while it is present in the dictionary.

Thank you very much.

[matthomson]

Hello! Apologies for responding so late - I must have missed this somehow.

To answer your questions:

1 - In case of grab sample should collPer be left empty?

• Yes! That’s exactly correct.

2 - In case of 2 or more grab samples done at the same site throughout the day and then pooled by the technician before sending to the laboratory. Each grab sample should be reported separately in sample table. The final pooled sample should also be reported. For this final sample is it correct if collDT stays empty and collDTtart and collDTEnd are completed respectively with the collection datetime of the earliest grab sample and collection datetime of the latest grab sample?

• Yes! Again, exactly correct. And it’s entirely appropriate to use collDTStart and collDTEnd for describing the range covered by the pooled sample. Plus, if the relationships between the pooled sample and the parent single samples have been defined in the sampleRelationships table, someone can easily find the discrete collection time for each of the grab samples.

3 - Also for the final grab sample what collType should be reported? Manual composite sample?

• I think you’re right that manual composite makes the most sense for this scenario.

4 - Manual composite sample (as well as Passive Sample - General and I think a Flow proportional sampleoption should be added too) is not descibed in the documentation while it is present in the dictionary.

• How odd! When I look at the documentation I see descriptions for each of these collection types (link: Sets – Public Health Environmental Surveillance Open Data Model (PHES-ODM) Documentation) and I also see all of them listed, including flow proportional. I suppose enough time has passed that it’s possible I had not yet updated the documentation site at the time of asking. If that’s what it was I apologize!