Forum Posts

Christos Astaras
Apr 13, 2020
In Enclosures
Hello everybody, I am going to place an order for ePTFE membranes, likely from this company on Alibaba. Before I email them to get quote in the next couple of days, is there anyone who wants to join this order? I am based in Greece. I will post your part of the order as soon I receive the membranes. I am likely going to order about 100-200 for myself. I would prefer the black color, but I am ok with switching to white if color is important for other people. I am also willing to consider other membranes instead of the one mentioned above, if you have good reason to believe they would perform better. By the way, I am thinking of placing the membrane on the inside surface of the box, and a single layer of 500-mesh woven on the outer side ( / instead of the 2-layer NicWax treated suggestion mentioned in another post - here ). Would the combination pose a problem? I am recording at 8KHz sampling rate only. I was thinking that the wire mesh would keep insects away (which have poked a hole in one of the two AudioMoths I have tried - see photo below), while also limiting the amount of water that would linger on the lip of the drilled hole - if I had only the membrane on the inside. Any thoughts? Looking forward to hearing from interested people. Christos
About to order ePTFE membranes - anyone wants to join order? content media
Christos Astaras
Oct 19, 2018
In Device Support
Hello AM community, We have a grant to deploy ~30 AMs at a temparate forest (severe winters/mild summers) to record continuously at 8KHz ambient sounds with emphasis on human activities. The goal is to promote the use of passive acoustic monitoring as a law enforcement monitoring tool for protected area managers, so it is critical that the tool is reliable and logistically "affordable" to operate (hence why we are looking at ideally a 3 month deployment time). We have successfully done that in Afrotropical settings using Wildlife Acoustic sensors/Cornell SWIFT sensors. I am considering using Audio Moths as I like their energy consumption, size, cost and ethos of the project. My concern is whether the AM is, in its current stage of development (i.e. 1.0.0 or 1.1.0), able to be deployed for 3 months. Specifically: a) Three months * ~1.3Gb data/day requires a 128Gb card. I understand that if formatted in FAT32 using specific software, the AM can handle such a card, right? Any issues from people who have tried such size cards? b) Batteries - I read in one forum post reply by Andy about the Belize project that with a 6V lantern batterry (24Ah + specific energy consumption set up) the AMs operated for 400 days. Oyr sensors have to record continuously. Has anyone used such size batteries for continuous recording who can share info on recording times achieved? c) Casing - given the battery size required, I can not use the neat/tidy small-size options that have been kindly shared in relevant forums. We can make our own casings I suppose from boxes for external electrical cabling etc. but I wonder whether anyone has successfully used for long deployments a case that can house such a large battery. I am aware of the Belize project case (PVC pipe) that the AM team has used, but that design is not available to order etc. just yet, right? d) Microphone cover - I understand that due to humidity there should be a fine wire screen mesh added at the bottom of the case (possibly over the microphone opening?) to let humidity out during the day. Have there been any issues with that? Has anyone used such wire screens with the AM (i.e. only screens without water proof membrane that apparently reduces - possibly significantly - the detection range of sounds)? e) Reliability issues - We have experiemented with 2 AMs already and occasionally the recorders did not record as expected (i.e. did not start, lost scheduling etc.). I am sure most of that is due to our handling or shaky batteries. Can someone comment on the reliability of continuous recording of the AM for >1+ deployments in temperate settings? The budget and project schedule is such that we basically have one shot at making this work. We will not be able to afford reverting to other sensors if the AMs do not work, and we really want to make people love passive acoustic monitoring and its potential. Hence, my post title. Is the AM - in the community's opinion - fit for purpose? I value the communtiy's collective feedback and look forward to reading it. Christos

Christos Astaras

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