OpenFlowMeter

Purpose

Measuring flow of gases and maybe liquids.

Principle

Measures the volume flow by the amount of heat transferred to a gas flow. This can be either done by constantly heating the sensor or by evaluating temperature cycles.

Hardware

The hardware is based around two voltage controlled current sources, which are controlled and readout via a STM32F103 microcontroller. The controller provides the ADCs for reading the voltages and current as well as the digital communication to the outside of the PCB.

Photographs of the populated PCB

<img width="90%" src="images/photographs/OFMv2.0_TOP.jpg" alt="Picture of the PCB from TOP side"> <img width="90%" src="images/photographs/OFMv2.0_BOT.jpg" alt="Picture of the PCB from BOT side">

References

The working principle of this device is adapted from a proposal of the LHC gas group at CERN. In addition there is a report of a student, explaining / proposing this technique more in detail.

[1] M. van der Klis. PT100 channel flow meter for the LHC experiments, Technical Student Report Feb. 2001

[2] F.Hahn, S.Haider, M. v.d. Klis, C. Zinoni, Proposal for a gas flow meter at LHC, 10.2.2001

PCBs

PCBs are available from AISLER https://aisler.net/p/MVHMBVKT