Rachel, did you considered that the flow meter may doesn't work properly? Sometimes I found it tricky to measure the flow and if the rubber ring don't fit perfectly to the opening of the trap it was shoing less-nothing.

Did the trap worked fine before?

All the best, Kai

Dear Rachel,

Kai has a good suggestion there because if the flow meter is not pushed firmly onto the air intake, it might not register all of the air flowing in. But assuming you checked the air intake of obstructions such as dead insects or spider's webs, another possibility is that the orifice at the base of the drum chamber, above the motor, could be partially blocked. For mains motors, you can remove the plastic insert and, or open the screw that partially restricts the air flow. If you have a 12volt motor, you could increase the motor power by turning the motor control clockwise.  If you have a 12V motor, another possibility could be that the motor spindle has snapped so the motor is still spinning but the turbine is not. If you changed the motor then this shouldn't be the problem.

Hi Kai and Jon,

Thanks for your suggestions!

We have an identical spore trap and the flow meter is reading correctly on that one so the flow meter is not the issue. We have checked the air intake for obstructions and the 12 volt motor is turned all the way up and the turbine is spinning. We have emailed the manufacturer, so hopefully they will have additional suggestions.

Hi achael

You can find some useful references on attachment 1

https://www.burkardscientific.co.uk/agronomics/hirst_spore_sampler.htm

2

https://www.burkard.co.uk/7dayst.htm

3

https://www.apsnet.org/publications/phytopathology/backissues/Documents/1983Articles/Phyto73n11_1526.pdf

4

http://www.shailrontechnology.com/gallery/upload/Burkard%20-%207%20DAYS%20Recording%20Volumetic%20Spore%20Trap%20System.pdf

5

http://www.aaem.pl/-b-b-Relative-efficiencies-of-the-Burkard-7-Day-Rotorod-and-Burkard-Personal-samplers-for-Poaceae-and-Urticaceae-pollen-under-field-conditions,72191,0,2.html

6

https://link.springer.com/article/10.1007/BF00429591

7

https://link.springer.com/content/pdf/10.1007%2F978-0-387-30253-9_4.pdf

8

https://aaaai.confex.com/aaaai/2013/mediafile/Handout/Paper1405/free/4db77adf5df9fff0d3caf5cafe28f496/Burkard%20Directions.pdf

9

https://pollen.utulsa.edu/levetinhallrogers.pdf

10

https://www.tandfonline.com/doi/pdf/10.1080/00173139809362683

11

https://www.tandfonline.com/doi/abs/10.1080/00173138909429966

12

https://www.indiamart.com/shailrontechnology/

13

https://ionicsporetrap.com/~ionicspo/uploads/File/DS%20catalog%202011.pdf

14

https://www.ncbi.nlm.nih.gov/pubmed/25528914

15

https://www.worldallergy.org/esp/ptm_2007.pdf

16

https://www.academia.edu/18815975/An_advanced_slit-type_volumetric_spore_trap_for_monitoring_bioaerosols_new_methods_for_identifying_fungal_spores

17

http://pure.au.dk/portal/en/publications/relative-efficiencies-of-the-burkard-7day-rotorod-and-burkard-personal-samplers-for-poaceae-and-urticaceae-pollen-under-eld-conditions(a328df87-52f5-4e96-be50-5e00692e7b58).html

18

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4328459/

19

https://books.google.com/books?isbn=8120326741

20

https://books.google.com/books?isbn=0080535771

you can use Air Flow Meter for checking sampler air leakage....