When measuring NO2, this holder extends the passive sampler tube further from the street pole allowing better air circulation. Furthermore provides protection from moisture clogging the green filter. Also makes exchanging the tubes on longer projects a breeze! 

Made for tube 13,1 mm in diameter. Attached to a street sign with 2 fast straps. Material PET-G. Made and tested in Prague by Senzorvzduchu, z.s. and ČHMÚ, project ARAMIS, consultation by Passam a.g. Switzerland. 

• Single or double holder for collocation.
• Two versions - long distance and shorter one. Use longer distance when obstructed from one side and better air flow is required.
• Made in two joining parts (holder and distance fixer) due to best and fast printing results without supports.
• added holder with flat surface to stick to window glass with doudle sided tape

Glue the distance fixer in single or double version to the NO2 tube holder. After drying sand the inner of the holder with round rasper (the tags on the tubes would otherwise stuck and make the removal of the tubes almost impossible).

Please note that even the PET-G lasts 8-9 months in open enviroment. After this period I experinced some breaking (especially the longer version). Can be sharp! Also when measuring in the city, grey finish colour is reccomended to hide from unwanted attention.