Posts made by secantscope

Hi there! Reading the Watermark sensor is no easy task indeed. Took us a while to get accurate and reliable data out of these sensors.

First of all, take a look at the official documentation provided by Irrometer: https://www.irrometer.com/200ss.html
Especially the pseudo-AC excitation is very important and make sure you calibrate the readings using the soil temperature.

There's quite some off-the-shelf hardware on the market already. Look for a device that has a low power consumption so you can measure throughout the year, for example:
https://www.crodeon.com/blogs/news/connecting-a-watermark-sensor-to-the-cloud

Let me know if you have any more questions!

Looking forward to their reply!

Keeps surprising me how hard it is to find something that easy. Of course I could simply use any kind of vented enclosure, but these seem less suited for outdoor use...

https://www.google.com/search?q=vented+sensor+enclosure&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjR8eSizKfoAhWEsaQKHfAvBK4Q_AUoAXoECAsQAw&biw=1920&bih=937

Thanks for your reply HectorAllen. For us it is worth the effort because we already have all the other components (power, processing, transmission, cloud, etc...) ready. We're just looking for a low-power sensor that we can add cabled...

@HectorAllen thanks for your reply. I wish I could go with these enclosures, but these are actual CO2 sensors that I found online. I'm having the hardest time finding the manufacturer of these enclosures...

If anyone knows who builds these enclosures, please let me know.

Hi all,

another day, another sensor request. We're currently looking to buy a CO2 sensor, such as one these for example:

https://www.gassensing.co.uk/product/cozir-lp-co2-sensor/
https://www.sensirion.com/en/environmental-sensors/carbon-dioxide-sensors/carbon-dioxide-sensors-co2/

What kind of enclosure would you recommend for this? Is any vented enclosure suitable, or should we look after a specific filter membrane, as picture here:

Thanks in advance!
secantscope

Hi Skywatch, thanks for your reply. We've looked into using decibel meters with USB or RS232 output, but this is tricky because these meters are not intended to operate 24/7 for years on end. And we don't want to write software to keep this meter on...

Dismantling is indeed an option but this is a lot of work.

Readings should be accurate but not to the legal level. So I guess the accuracy of a €200 decibel meter from amazon should be fine.

I guess there's no affordable sensors on the market because they are not frequently bought...

@Nca78 said in Enclosure for Honeywell HPM-series PM sensor:

For enclosure, another option is a radiation shield.

What do you mean by "radiation shield"?

Hi all,

For a new project I'm looking at decibel sensors. I found some very expensive options from Cirrus (UK), Cesva (PL) or Libelium (ES). They all cost €1000 or more. And most of them are on 12V or more.

Does anyone know a good alternative (on price and/or on voltage)? I would prefer 5V or less.

It surprises me that decibel sensors are so hard to find, while tons of decibel meters are available on Amazon for very reasonable prices...

Thanks for your replies!

Hi Yveaux and Nca78, thanks a lot for taking the time to answer.

My german is rusty but I understand they're just hiding the sensor in a plastic pipe. That's a really shady way of "protecting" the sensor. Bugs would have the time of their life in these pipes. Also, it doesn't look professional at all.

@Nca78 The lower accuracy is remarkable as they are a lot more expensive. The original model is priced at €14 on TME, while the compact is €58 on Mouser

I don't understand why Honeywell doesn't provide a simple policarbonate case for these models...

Another famous sensor of this kind is the SPS30 by Sensirion. That one is even more compact, but again there's no standard enclosures on te market...

Hi all,

I'm new to this forum, but this place seems really interesting. So very high chance you'll see me again around here!

For a project we're currently looking at the HPM-series particle matter sensor from Honeywell:
https://sensing.honeywell.com/sensors/particle-sensors/HPM-series

This seems to do everything I want, and it's even suited for use in harsh enviroments (see link above).

However: i don't think we are supposed to place this sensor outdoor just like that in the open air? There should be some kind of enclosure around this, right? I would need a protective case that fits the sensors air-intake and exhaust openings and my waterproof connector. Been googling for quite some time but there's no cases on the market for a sensor that seems quite popular...

What would you recommend? Thanks in advance!