Measurement steps and existing problems of sharp dn7c3a006 PM2.5 sensor

Recently the company wanted to do a PM2.5 testing equipment, probably studied the PM2.5 related knowledge, as well as sharp dn7c3a006 sensor applications.

The following is a brief introduction to it.

1, its own dust-free voltage (nodust_v), the nominal temperature (base_temp), the two values are scanned by a QR code, such as the scan we purchased to obtain the "149190104F 1.31 * * * * 25.8", can be obtained nodust_v = 1310mv, Base_temp = 25.8 ℃ (but these two values only serve a certain reference, but are not absolutely accurate);

2, according to the above two values, and then measured properly under the ambient temperature temp to obtain the reference voltage Vs, the specific reference:

3, the recurrent ad sampling to get the output voltage Vo, the timing is as follows:

4, preliminary estimate PM2.5 concentration measurement value:

PM2.5 level (UG/M3) = 0.6X⊿MV (⊿mv = Vo–vs;)

which α is 0.6 is the experience value, may need to adjust,

5, the PM2.5 concentration measurement is also affected by the atmospheric humidity, but also to add a correction factor β, wherein the β is a humidity transmitter detected value, the specific reference is as follows:

The PM2.5 concentration measurement can be obtained through the above:

PM2.5 level (ΜG/M3) =αxβx (VO[MV]–VS[MV]);

6, but at this time and the standard may have a certain error, but also need to correct:

There is no further reference provided here, but the general correction procedure is corrected by a checklist;

However, the temp, β is real-time change, α is the empirical value, Nodust_v and base_temp are only reference values, the actual may also need to be modified, and each sensor device is different;

When the above variables change at the same time, how to adapt to each environment and can get the exact value of the problem;

7. In addition, official documentation gives limitations to the measuring range:

The accuracy is described as follows:

Noting that their previous documentation was not given accuracy, the above-mentioned accuracy authority is a problem, as follows:

8, for the sharp dn7c3a006 sensor detection PM2.5 using the Ray method, and for the general infrared Ray. This method is also affected by the detection of particle color, material, such as silica and gold dust test results will be large differences;

This sensor can be used as a toy for personal use. To be commercially available for accurate measurement, the individual is considered to be less likely.

The above only represents a personal point of view, if you have carefully studied PM2.5 related testing or related sensors, welcome guidance, will be very grateful.

Measurement steps and existing problems of sharp dn7c3a006 PM2.5 sensor