Dear all,
I would like to share our experience of finding suitable case for audiomoth.
First of all, our study aims to evaluate the hunting pressure over the vulnerable Red-breasted Goose (Branta ruficollis) within the roosting areas (mostly natural lakes) in SE Romania during the winter period when the geese are inhabiting those wetlands.
We have selected this junction box, which were quite cheap, 0.61 Euro: https://www.dedeman.ro/ro/doza-derivatie-goala-2000016-ip54-75-x-75-x-36-mm/p/1001357
Certified as IP54 with dimensions, 75 x 75 x 36 mm, very much closer to the size of the audiomoth. Those two ears makes the installation with plastic strips much easier, especially on tree branches. We have tested those junction boxes under water (over 30 min) and we have found just some drops inside, so it should resist on any water jets. In our study region we might have rain and snowfall, mixed with some freezing temperatures.
Small 5 mm hole was drilled of the case’ cap where the microphone is located and covered by waterproof acoustic membranes (IP67), ordered from https://voir.en.alibaba.com/product/60380452525-801219240/e_PTFE_acoustic_membrane_for_speaker_and_mic_IP67_waterproof_sticker.html. The membranes are coming with some really strong adhesive around the margins, so no chance of falling down.
To avoid any possible movements of the audiomoth inside the box we have glued the device to the case cap with double sided adhesive tape, looking carefully to place the microphone over the drilled hole. The adhesive type was so strong that we have managed to dispatch the circuit board from the battery compartment! Than we used some small pieces of isolating material to seal the space in the box, in order to prevent possible movements due to strong wind.
In order to create some camouflage effects of the box we sprayed the boxes with two different colors, because we don’t want the hunters to see our boxes:).
To ensure much more water resistance of the box we used some durable, waterproof, one-sided adhesive tape to seal the box. Finally, the box was fastened of the tree branches with those plastic strips, mention above.
That’s all. I hope all is set well and we will have good recordings.
All the best,
Emil
Hi all, I also want to buy the acoustic membranes. Has anyone ordered from a supplier at the US? Or any other supplier, besides Alibaba?
Hello Emil,
Have you noticed a "clicking" sound on your recordings at lower frequencies (~5-30kHz) with the AudioMoth inside the case? See here for why I ask - https://www.openacousticdevices.info/support/main/comment/5dce2a2732c0dc00170ca837
Hi Emil, The company has now informed me that the model you used has been discontinued - they didn't provide any further information as to its ability to let sound through. I'll be ordering one of the newer models and can update here later once tested. Cheers, Thomas
Hi Thomas,
I cannot open the links you have sent. However, for me the acoustic membranes (model: M007) works pretty well and I had no obstruction of the recordings.
Cheers,
Emil
Hi Emil, Thank you for the great description of your case. I think we might be using an adapted version of your design in our study. I have a question regarding the acoustic membrane. The company has agreed to sell a smaller sample of <1000 units, however has told me the model you suggest in your link ( #M007 ) doesn't let sound through. Instead, he recommended models #SA016 or #SA128. Attached you can see their performance summary sheet. Any insights as to what might be going on with the different membranes? Cheers, Thomas
Cheers, Thomas
Thank you for sharing!
Hi there,
I have managed to withdraw part of the devices from the field. All of them safely, no losses. Perfect recordings. The batteries managed to resist appr. 90 days. The problem is with the membranes. Almost all of them were punched. We suppose that due to the freezing temperature over the winter, the membranes were frozen and then when the temperatures rise they got punched. Attached is one photo.
The acoustic stickers are ridiculously expensive - shipping to USA with minimum order of 1000 stickers is $500 US (currently about € 441.37 EUR ). Has anyone found a vendor selling these in smaller batches?
Have you tested the membrane to see how much sound is attenuated?