I am building out an airflow testing rig and I’m using 16 airflow sensors. I realized that there is a difference in values for the different sensor when measuring the same air speed. I don’t think it’s dirt because all the sensors are new and I just assembled them. I measured the voltage across being supplied to the sensor and they are different, could this cause the difference in values. Also is the Vreg supposed to be connected to my 3.3v supply? It is not shown on the data sheet but I’m wondering if that’s part of the issue.
Also does shorting the board damage it?
Hello,
Thanks for reaching out Renesas Engineering Community.
Could you please specify the exact part number of the flow sensor you are using? Also could you please specify to us how do you pass airflow through the sensor? Also we would appreciate it if you could provide us some of the measurement samples you get while measuring the same airflow from all the the flow sensors you use.
I would suggest to you to check also this document to find out how are our flow sensors working and what are the factors that can influence the measurements and the accuracy of the flow sensor:
https://www.renesas.com/us/en/document/apn/factors-influencing-accuracy-thermal-flow-sensors?r=1395551
Regarding the VREG pin as mentioned in the datasheet this pin is marked as the ADC input reference pin.
On the datasheet this pin is connected to GND:
Also if you will check the Schematic for US082-FS3000EVZ we provide:
https://www.renesas.com/us/en/document/mat/us082-fs3000evz-evaluation-board-manual?r=1515556
You will see it is also connected to GND:
However if you select to connect it also on VCC (3.3V) the sensor should work with no issue.
Hope it helps.
Best Regards,
IK