--- title: Access Sensor Technologies' Blog | UPAS v2.1 description: UPAS v2.1 | Advice for collecting air samples using Access Sensor Technologies' Ultrasonic Personal Air Sampler (UPAS) and Home Health Box (HHB). --- [Skip to content](https://www.accsensors.com/blog/tag/upas-v2-1#main-content) [![AST](https://www.accsensors.com/hs-fs/hubfs/AST.jpg?width=2303&height=774&name=AST.jpg)](https://www.accsensors.com/) - [Products](https://www.accsensors.com/products) Show submenu for Products - [UPAS v2.1](https://www.accsensors.com/upasv2.1) - [UPAS v2.1 PLUS](https://www.accsensors.com/upasv2.1plus) - [UPAS v2.0](https://www.accsensors.com/upasv2.0) - [Home Health Box](https://www.accsensors.com/indoor_sampling) - [Inlets and Accessories](https://www.accsensors.com/accessories) - [UPAS Outdoor Enclosure](https://www.accsensors.com/upas_outdoor_enclosure) - [Sample Analysis Services](https://www.accsensors.com/sample_analysis) - Technical Resources Show submenu for Technical Resources - [Applications Blog](https://www.accsensors.com/blog) - [R Shiny Application](https://accsensors.shinyapps.io/shinyAST/) - [astr R Package](https://github.com/accsensors/astr) - [YouTube](https://www.youtube.com/channel/UCbbSB_ja8JY-xX90D94qyKA) - Contact Us Show submenu for Contact Us - [Request Free Demo](https://www.accsensors.com/freetrial) - [Request a Quote](https://www.accsensors.com/quote) - [Request Support](https://www.accsensors.com/support-request-form) - [Our Team](https://www.accsensors.com/about) - [Distributors](https://www.accsensors.com/distributors) Open main navigation Close main navigation - [Products](https://www.accsensors.com/products) Show submenu for Products - [UPAS v2.1](https://www.accsensors.com/upasv2.1) - [UPAS v2.1 PLUS](https://www.accsensors.com/upasv2.1plus) - [UPAS v2.0](https://www.accsensors.com/upasv2.0) - [Home Health Box](https://www.accsensors.com/indoor_sampling) - [Inlets and Accessories](https://www.accsensors.com/accessories) - [UPAS Outdoor Enclosure](https://www.accsensors.com/upas_outdoor_enclosure) - [Sample Analysis Services](https://www.accsensors.com/sample_analysis) - Technical Resources Show submenu for Technical Resources - [Applications Blog](https://www.accsensors.com/blog) - [R Shiny Application](https://accsensors.shinyapps.io/shinyAST/) - [astr R Package](https://github.com/accsensors/astr) - [YouTube](https://www.youtube.com/channel/UCbbSB_ja8JY-xX90D94qyKA) - Contact Us Show submenu for Contact Us - [Request Free Demo](https://www.accsensors.com/freetrial) - [Request a Quote](https://www.accsensors.com/quote) - [Request Support](https://www.accsensors.com/support-request-form) - [Our Team](https://www.accsensors.com/about) - [Distributors](https://www.accsensors.com/distributors) - [Try for Free](https://www.accsensors.com/freetrial) [Try for Free](https://www.accsensors.com/freetrial) # Air Sampling Made Simple Blog This is a search field with an auto-suggest feature attached. - There are no suggestions because the search field is empty. [![A diagram pointing out the features that can be used to distinguish the UPAS v2.0, UPAS v2.1, and UPAS v2.1 PLUS](https://www.accsensors.com/hubfs/BlogPost_WhichUPAS_Cover.png)](https://www.accsensors.com/blog/which-upas) ## [Which UPAS model do I have?](https://www.accsensors.com/blog/which-upas) ![Picture of Jessica Tryner](https://www.accsensors.com/hs-fs/hubfs/JT_20250309_square.jpeg?width=50&name=JT_20250309_square.jpeg) [Jessica Tryner](https://www.accsensors.com/blog/author/jessica-tryner) May 26, 2026, 5:58:14 PM Access Sensor Technologies has sold three different versions of our Ultrasonic Personal Air Sampler ... [![A photograph of a workstation with a multimeter, computer, and soldering iron.](https://www.accsensors.com/hubfs/BlogPost_Service_CoverImage-1.jpg)](https://www.accsensors.com/blog/upas-service) ## [What to expect when returning your UPAS for service](https://www.accsensors.com/blog/upas-service) ![Picture of Jessica Tryner](https://www.accsensors.com/hs-fs/hubfs/JT_20250309_square.jpeg?width=50&name=JT_20250309_square.jpeg) [Jessica Tryner](https://www.accsensors.com/blog/author/jessica-tryner) Mar 10, 2026, 3:36:42 PM Step 1: Fill out the Support Request Form If you think you need to send your UPAS to us for service—... [![A photograph of a person wearing a UPAS v2.1 PLUS on a cross-body backpack strap.](https://www.accsensors.com/hubfs/BlogPost_WearingTheUPAS_CoverImage.jpg)](https://www.accsensors.com/blog/wearing-the-upas) ## [Wearing the UPAS](https://www.accsensors.com/blog/wearing-the-upas) ![Picture of Jessica Tryner](https://www.accsensors.com/hs-fs/hubfs/JT_20250309_square.jpeg?width=50&name=JT_20250309_square.jpeg) [Jessica Tryner](https://www.accsensors.com/blog/author/jessica-tryner) Feb 25, 2026, 11:28:17 AM "How do people wear the UPAS?" Below, we discuss factors you should consider when figuring out the b... [![A photograph of a UPAS v2.1 PLUS with a PM10 inlet installed. The focus of the image is the end of the UPAS housing where the microSD card is installed.](https://www.accsensors.com/hubfs/Blog_UPASFirmwareRev206_CoverImage.jpg)](https://www.accsensors.com/blog/upas-firmware-rev206) ## [Another UPAS firmware update: What’s new in rev206?](https://www.accsensors.com/blog/upas-firmware-rev206) ![Picture of Jessica Tryner](https://www.accsensors.com/hs-fs/hubfs/JT_20250309_square.jpeg?width=50&name=JT_20250309_square.jpeg) [Jessica Tryner](https://www.accsensors.com/blog/author/jessica-tryner) Oct 27, 2025, 9:23:46 PM In May 2025, we released a major update to our UPAS v2.1 and v2.1 PLUS firmware, named “rev200.” Sin... [![A photograph of a UPAS v2.1 PLUS with a respirable PM inlet installed. A PM10 inlet and a flow check adapter are also sitting nearby in the image.](https://www.accsensors.com/hubfs/NewFirmwareBlog_CoverImage.jpg)](https://www.accsensors.com/blog/new-firmware) ## [Introducing the new UPAS v2.1 and v2.1 PLUS firmware](https://www.accsensors.com/blog/new-firmware) ![Picture of Jessica Tryner](https://www.accsensors.com/hs-fs/hubfs/JT_20250309_square.jpeg?width=50&name=JT_20250309_square.jpeg) [Jessica Tryner](https://www.accsensors.com/blog/author/jessica-tryner) May 12, 2025, 8:19:23 PM Access Sensor Technologies has improved our UPAS v2.1 and UPAS v2.1 PLUS firmware to make UPAS opera... [![A photograph of air quality monitoring instruments at the CAMP site in Denver, Colorado](https://www.accsensors.com/hubfs/CAMP_site_cover_photo.jpg)](https://www.accsensors.com/blog/upas-collocation-with-regulatory-monitors) ## [UPAS Collocation with Regulatory Monitors](https://www.accsensors.com/blog/upas-collocation-with-regulatory-monitors) ![Picture of Jessica Tryner](https://www.accsensors.com/hs-fs/hubfs/JT_20250309_square.jpeg?width=50&name=JT_20250309_square.jpeg) [Jessica Tryner](https://www.accsensors.com/blog/author/jessica-tryner) Nov 4, 2024, 8:10:37 AM How do outdoor particulate matter concentrations measured using Ultrasonic Personal Air Samplers (UP... [![](https://www.accsensors.com/hubfs/Blog_OutdoorSampling_CoverPhoto-1.jpg)](https://www.accsensors.com/blog/participant-initiated-sampling) ## [Participant-initiated sampling in California's Central Valley](https://www.accsensors.com/blog/participant-initiated-sampling) ![Picture of Jessica Tryner](https://www.accsensors.com/hs-fs/hubfs/JT_20250309_square.jpeg?width=50&name=JT_20250309_square.jpeg) [Jessica Tryner](https://www.accsensors.com/blog/author/jessica-tryner) Oct 18, 2024, 9:19:08 AM Do you want to design a project in which study participants initiate and collect multiple consecutiv... [![Map of time zones around the world](https://www.accsensors.com/hubfs/World_Time_Zones_Map.png)](https://www.accsensors.com/blog/working-with-timestamps-in-upas-log-files) ## [Working with timestamps](https://www.accsensors.com/blog/working-with-timestamps-in-upas-log-files) ![Picture of Jessica Tryner](https://www.accsensors.com/hs-fs/hubfs/JT_20250309_square.jpeg?width=50&name=JT_20250309_square.jpeg) [Jessica Tryner](https://www.accsensors.com/blog/author/jessica-tryner) Oct 16, 2024, 12:02:10 PM Timestamps in UPAS log files In log files written by Ultrasonic Personal Air Samplers (UPAS), you'll... [![A photograph of a person getting ready to install a filter cartridge in an air sampler](https://www.accsensors.com/hubfs/Blog_FilterHandling_Featured.jpg)](https://www.accsensors.com/blog/how-to-handle-and-install-filter-cartridges) ## [How to handle and install filters and filter cartridges](https://www.accsensors.com/blog/how-to-handle-and-install-filter-cartridges) ![Picture of Jessica Tryner](https://www.accsensors.com/hs-fs/hubfs/JT_20250309_square.jpeg?width=50&name=JT_20250309_square.jpeg) [Jessica Tryner](https://www.accsensors.com/blog/author/jessica-tryner) Sep 30, 2024, 1:14:42 PM Are you new to particulate matter (PM) sampling? Have you purchased sample analysis services through... [![Photograph of UPAS inside a laboratory test enclosure](https://www.accsensors.com/hubfs/Blog_DutyCycling_Header-1.jpg)](https://www.accsensors.com/blog/all-about-duty-cycling) ## [All about duty cycling](https://www.accsensors.com/blog/all-about-duty-cycling) ![Picture of Jessica Tryner](https://www.accsensors.com/hs-fs/hubfs/JT_20250309_square.jpeg?width=50&name=JT_20250309_square.jpeg) [Jessica Tryner](https://www.accsensors.com/blog/author/jessica-tryner) Aug 5, 2024, 9:30:56 PM What is duty cycling? Duty cycling refers to the practice of operating the Ultrasonic Personal Air S... [![Photograph of UPAS on workbench](https://www.accsensors.com/hubfs/UPAS_at_workstation.jpeg)](https://www.accsensors.com/blog/regular-maintenance) ## [Regular Maintenance](https://www.accsensors.com/blog/regular-maintenance) ![Picture of Thomas Reilly](https://app.hubspot.com/settings/avatar/800cc6b0112e54f2e88c4f26c133c3dc) [Thomas Reilly](https://www.accsensors.com/blog/author/thomas-reilly) Mar 6, 2024, 5:14:04 PM Our air samplers are durable. A customer once sent a UPAS in for service that had a record 8000+ hou... [![](https://www.accsensors.com/hubfs/IMG_7663%20Large.jpeg)](https://www.accsensors.com/blog/wheres-the-noise-wheres-the-pulsation-a-quick-explainer-on-what-makes-upas-technology-special) ## [Where’s the Noise? Where's the Pulsation? A quick explainer on UPAS technology.](https://www.accsensors.com/blog/wheres-the-noise-wheres-the-pulsation-a-quick-explainer-on-what-makes-upas-technology-special) ![Picture of Thomas Reilly](https://app.hubspot.com/settings/avatar/800cc6b0112e54f2e88c4f26c133c3dc) [Thomas Reilly](https://www.accsensors.com/blog/author/thomas-reilly) Mar 27, 2023, 8:30:54 PM We’re a team of mostly scientists and engineers and that means we’re going to come up with nerdy som... ###### [Products](https://www.accsensors.com/products) [UPAS v2.1](https://www.accsensors.com/upasv2.1) [UPAS v2.1 PLUS](https://www.accsensors.com/upasv2.1plus) [UPAS v2.0](https://www.accsensors.com/upasv2.0) [Home Health Box](https://www.accsensors.com/indoor_sampling) [Inlets and Accessories](https://www.accsensors.com/accessories) [UPAS Outdoor Enclosure](https://www.accsensors.com/upas_outdoor_enclosure) [Sample Analysis](https://www.accsensors.com/sample-analysis) ###### Technical Resources [Applications Blog](https://www.accsensors.com/from-the-access-sensor-tech-team) [R Shiny Application](https://accsensors.shinyapps.io/shinyAST/) [astr R Package](https://github.com/accsensors/astr) [YouTube](https://www.youtube.com/channel/UCbbSB_ja8JY-xX90D94qyKA)       ###### Contact Us [Request a Free Demo](https://www.accsensors.com/freetrial) [Request a Quote](https://www.accsensors.com/quote) [Request Support](https://www.accsensors.com/support-request-form) [Our Team](https://www.accsensors.com/about) [Distributors](https://www.accsensors.com/en-us/distributors) [contact@accsensors.com](mailto:contact@accsensors.com)     ###### Legal [Privacy Policy](https://www.accsensors.com/privacypolicy) [Terms and Conditions](https://www.accsensors.com/termsanduse) [FCOI](https://www.accsensors.com/fcoi)         [linkedin-in icon](https://www.linkedin.com/company/access-sensor-technologies/mycompany/?viewAsMember=true) [Check out our YouTube channel.](https://www.youtube.com/channel/UCbbSB_ja8JY-xX90D94qyKA) [Link to our GitHub](https://github.com/accsensors) --- Access Sensor Technologies | 320 E Vine Dr. Ste. 221 | Fort Collins, CO 80524