<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>hammock</author><text>The same is true of digital bathroom scales. In fact almost all consumer grade digital scales have “fake accuracy” built into the firmware that ensures the same exact weight shows up when you step on the scale twice in a row, even if you pick up e.g a quarter-pound weight in your hand the second time</text><parent_chain><item><author>ahaucnx</author><text>Author here.&lt;p&gt;I wrote this article a few weeks ago after discovering that a well known air quality monitor in the market that retails for more than USD 1000 actually uses a PM module that costs less than USD 20.&lt;p&gt;Often people assume that the more expensive, the better but as you can see in the article this is often not the case -especially when it comes to the accuracy of the monitor.&lt;p&gt;If you are looking for an open source &amp;#x2F; open hardware air quality monitor kit that uses high quality sensor modules and is very easy to assemble, have a look at the project we maintain. Instructions to built an indoor monitor [1], instructions to built an outdoor monitor [2] and overview of the kits [3]. All is open source (firmware, schematics, 3d files for enclosure, etc).&lt;p&gt;[1] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.airgradient.com&amp;#x2F;open-airgradient&amp;#x2F;instructions&amp;#x2F;diy-pro-v42&amp;#x2F;&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.airgradient.com&amp;#x2F;open-airgradient&amp;#x2F;instructions&amp;#x2F;di...&lt;/a&gt;&lt;p&gt;[2] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.airgradient.com&amp;#x2F;open-airgradient&amp;#x2F;instructions&amp;#x2F;diy-open-air-presoldered-v11&amp;#x2F;&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.airgradient.com&amp;#x2F;open-airgradient&amp;#x2F;instructions&amp;#x2F;di...&lt;/a&gt;&lt;p&gt;[3] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.airgradient.com&amp;#x2F;open-airgradient&amp;#x2F;kits&amp;#x2F;&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.airgradient.com&amp;#x2F;open-airgradient&amp;#x2F;kits&amp;#x2F;&lt;/a&gt;</text></item></parent_chain></comment><story><title>Air quality monitors: paying more does not get you more accuracy</title><url>https://www.airgradient.com/open-airgradient/blog/expensive-air-quality-monitors-not-more-accurate/</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>dognotdog</author><text>While I admire the efforts of the SC-AQMD, and generally agree with the article, using R2 from a higher-end, but not quite perfect instrument, can be quite misleading, and is not a great indicator of actual sensor performance. Also, there are a lot of potential improvements in sensor tech, but instead almost everyone is relying on the same cheap sensor modules instead of innovating, which have have pretty bad deficiencies, especially in detecting particulates in the ultra-fine range, and don’t age very well. But, they are the cheapest.</text><parent_chain><item><author>ahaucnx</author><text>Author here.&lt;p&gt;I wrote this article a few weeks ago after discovering that a well known air quality monitor in the market that retails for more than USD 1000 actually uses a PM module that costs less than USD 20.&lt;p&gt;Often people assume that the more expensive, the better but as you can see in the article this is often not the case -especially when it comes to the accuracy of the monitor.&lt;p&gt;If you are looking for an open source &amp;#x2F; open hardware air quality monitor kit that uses high quality sensor modules and is very easy to assemble, have a look at the project we maintain. Instructions to built an indoor monitor [1], instructions to built an outdoor monitor [2] and overview of the kits [3]. All is open source (firmware, schematics, 3d files for enclosure, etc).&lt;p&gt;[1] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.airgradient.com&amp;#x2F;open-airgradient&amp;#x2F;instructions&amp;#x2F;diy-pro-v42&amp;#x2F;&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.airgradient.com&amp;#x2F;open-airgradient&amp;#x2F;instructions&amp;#x2F;di...&lt;/a&gt;&lt;p&gt;[2] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.airgradient.com&amp;#x2F;open-airgradient&amp;#x2F;instructions&amp;#x2F;diy-open-air-presoldered-v11&amp;#x2F;&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.airgradient.com&amp;#x2F;open-airgradient&amp;#x2F;instructions&amp;#x2F;di...&lt;/a&gt;&lt;p&gt;[3] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.airgradient.com&amp;#x2F;open-airgradient&amp;#x2F;kits&amp;#x2F;&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.airgradient.com&amp;#x2F;open-airgradient&amp;#x2F;kits&amp;#x2F;&lt;/a&gt;</text></item></parent_chain></comment><story><title>Air quality monitors: paying more does not get you more accuracy</title><url>https://www.airgradient.com/open-airgradient/blog/expensive-air-quality-monitors-not-more-accurate/</url></story>