The last monitor I built, the Pickle was based on the PPD60PV-T2. It was super cool to see that adding the fan fused to the T2 would improve the performance so much that it worked pretty close to the AES-1 from Shinyei.
However, the T2 is kinda expensive and I wanted to see if the same fan idea would work with the cheaper sensors, the PPD42 in particular. As a result, I built the Pickle Jr – which is the 42 with the fan connected to the same Arduino Ethernet I used for the T2. I did the same thing as with the T2 i.e. added the L-shaped connector from Rain Drip and then fitted the fan on top.
So the Rain Drip is cut just like for the T2 and then glued with black epoxy to the 42. The challenge with the 42 is that there is no circular hole at the bottom of the plastic enclosure so I had to cut a ⅜” hole thru the plastic. It was tough as the top lid kept wanting to come off. But it worked at the end. Then I snipped off the heater resistor as well. The T2 had different connectors for the heater but the 42 does not.
It looks slanted, but it is not, this is due to the weight of the fan+Raindrip.
The fan is a Sunon that is rated for 5v, but I plugged it into the spare 3.3v connection on the Arduino.
So air flows into the top opening of the 42 and is sucked out by the fan at the bottom. It is pretty airtight, as a next step I am going to remove the cable tie as well – I did not use the cable tie for the T2.
Next…Measuring and Calibrating the 42 with fan….
indiaairquality 
Hi,
It’s nice to see more people doing such projects. I am trying to make a similar PM2.5 sensor. And so far I have tried to make one with the small Sharp Dust sensor. It comes out very noisy and unconvincing and I have decided to try the Shinyei dust sensors. The PPD42 is fairly common, but the others not so much. Please tell me where have you bought the sensors from and for how much.
Thanks
Hello,
All these sensors are pretty noisy and they need either post processing and smoothing of the data and/or an increase in sensitivity and more air flow as I have described. I get my sensors from whoever has them on sale – usually seed studio and they typically cost $15 or so. The DSM501 ones are cheaper than that. Good luck!
A.J.
Hi,
I have already purchased both of these(still waiting for the delivery) but I was thinking of trying the PPD60 and the AES-1. Shiney told me they dont work with private individuals and what I found in Europe was PPD60 – $200 and AES-1 – $700. I was wondering where did you det yours?
The latest thing I found in terms of dust sensor is this : http://www.sensor-air.com/index.php/products/air-quality-sensor-module/laser-particle-sensor-module-pm2003
I am currently waiting for a reply with prices.
Yanaki
I got these as I was/am working on a larger project so Shinyei sold me the AES-1. $700 is a good price for the AES-1, I paid $1000!
On the PM2003, I think that is expensive please let me know your price. I am going to test the SDS011 shortly.
Regards,
A.J.
Hi,
You are right the price they gave me is $125 for the PM2003 and $50 for the SDS011(from alibaba.com).
And the sales person told me that they are essentially the same, but one has a vaccum pump and the other a simple fan. I will order some of the SDS011 and make some tests too but that will be no sooner than a month and a half. In the meantime good luck with your test.
Yanaki
Hello Yanaki. Have you done tests on SDS011, or comparison with the ppd42?
Regards.
I’m also curious about the SDS011 test
Do you know why the dust sensor in the Xiaomi Air Purifier which looks like a DSM501A (~ the one on this page) picks up on steam from my shower? Is that a common problem of dust sensors?
Hi, excellent project. I now it has been a while but I wanted to ask you if you reinstalled the heater resistor because in your post you said “Then I snipped off the heater resistor as well”. Was it affecting the measures accuracy?