We have been trying to create a bettery supplied energy sensor technology to detect cigarette smoke, we want to be able for the sensor to last for months before having to recharge the battery, most of the smoke sensors in the market such as PM 2.5 have high energy consumption hence cannot be used to detect in small intervals smoking incidents. Even if we try to sleep the sensor for long period of times its capabilities decrease and it is no longer accurate. Anyone has a suggestion of alternative technologies that we can implement either on possible smoke sensors or other sensors that could possibly combined with software logic be reliable in detecting such incidents? Note: that we are trying to build this technology from scratch.
#We have been trying to create a bettery supplied energy sensor technology to detect cigarette smoke,
glass marlin
jaunty nest
What kind of response time do you need for detecting cigarette smoke?
How long does the sensor need to be powered to make a reliable reading?
Can you just add more batteries or make it rechargeable if it's portable, or mains powered if not?
Can you use a secondary, low power sensor to limit when you are testing for smoke - e.g standard smoke detectors run for years on a 9V - can you use that and then only when smoke is detected use your secondary sensor to see if it's from a cigarette - or even simpler, motion/presence detector - if there's noone there, there won't be any cigarette smoke
glass marlin
Hello, 1. I would say anything less than 5 minutes would be sufficient 2. The general metrics say that a PM2.5 sensor would need 30 seconds to 2 minutes of warm up before making a reliable metric. 3. It has to be in limited sizing to be fit inside apartments so that would not be possible, we aim to make it rechargable but we dont want to be a small frame time 4. This recommendation would be good but is it possible for these sensors to detect low amount of smoke because it will be much less if the smoke comes from cigarettes
@jaunty nest
jaunty nest
Yeah, with a 30-120s warmup time you're not going to gain much there anyway
What's wrong with just having something that is mains powered? No batteries at all
paper jolt
why isn't a conventional photoelectric smoke detector sufficient?
it does look like most commercially available detectors specifically for cigarette smoke require a wired power source, tho.
(should note that a conventional photoelectric detector with sensitivity tuned to detect cigarette smoke will probably be prone to nuisance alarms from kitchen/cooking even more than usual)
glass marlin
I have to contact with the person who is an expert but i guess there is a reason these sensors cannot be used for cigarette incident detection
@jaunty nest
can you answer me as well please
jaunty nest
Then your only real option is a bigger battery.
First one I looked at seems to have a 2mA standby current, 100mA max working current for 10s for a reading. If we say 1 reading per 5 minutes that's an average current draw of 5.2mA or 46Ah/year
Your best case with some rechargeable 18650 batteries is 3.6Ah - so that's 13 batteries to get a year of operation
Basically - you are running against hard limits here.
I get the impression this is what? A university project?
You sometimes simply cannot meet the specs
thorny jacinth
if you're ok with 10 minute updates, there's https://shop.ecowitt.com/products/wh43?srsltid=AfmBOop2owuq4WQepEnEGXo9UZf7KqLD9XucbgoeLptmpv1CjwdjPf-3 that integrates with the base station(which integrates with HA well and isn't cloud based)
paper jolt
That product page curiously does not mention how long the device is expected to last on batteries tho. Wouldn't be very good if it needs a new set every couple months or something :(
thorny jacinth
That product page curiously does not mention how long the device is expected to ...
after reading some reviews it doesn't sound like very long unfortunately, why not just a super long usb cord and just hide it in the corners of the walls and transition from ceiling to wall?
lime perch
If this is a commercial installation, the smoke detectors likely already have mains power backup available too
But anything sensitive enough to pick up cig smoke is likely going to throw plenty of false alarms for cooking
paper jolt
retrofits for older apartment buildings (like where i live) often do have battery powered smoke detectors :/