I have statred collecting PM samples from Qosain Scientific sampler. Sampler was running good and normal with average flow rate of 22 liters/minute. However when we set duration for 24 Hrs continuous sampling, the sampler not records data for complete 24 hrs. Rather it stops taking data like after recording it for 15 hrs approximately. Initially we thought that may be sampler memory is full. But even after erasing the previous data, sampler not recorded the data for 24 hrs duration, although sampler remained collecting particulate matter during this whole time, but it never recorded data. Moreover this has happened twice in two different timings, so it is not by chance incident (Please see the excel files attached).
Sampler worked fine and recorded well the data for 12 Hrs. Even it worked well and recorded data for a duration of 18 Hrs continuous sampling (Please see the excel files attached).
Only problem is when we do sampling for 24 Hrs, sampler works in operation for 24 Hrs, but not records data for 24 Hrs, rather collect information for only 12 to 15 hrs data. At the end not mentioned any session complete message or something like that. Moreover in 24 Hrs duration file, in the time duration cell of the sheet, in both two times duration of 05:47 is written, which is illogical as we have set time duration of 24 Hrs. (Please see the excel files attached).
For your convivence I have renamed correct files as normal along with sampling duration and problematic files as abnormal along with sampling duration.