Calibration

A cheap hand-held anemometer would allow you to calibrate velocity within a mph or better. If you get lots of calibration points over a decent range of wind speeds, you should be able to get a pretty reliable calibration curve for your custom instruments.

A more expensive anemometer and a pressure transducer will give you better calibration. Just depends on what you can spend on it. You might be able to rent high quality equipment from someone nearby.

The measurement of velocity or pressure is not a "calibration reading". Calibration referrs to the validity of the measurement. In other words, a measurement instrument can be calibrated so that one knows that the reading from that measureing equipment is correct.

To calibrate an instrument you need to first determine if it is currently in calibration (currently providing correct measurements). Then, if you find that it is out of calibration (measurements are not correct), you will need to adjust the instrument which most people are not qualified to do. In this case you want to send the instrument out to a calibration house which can provide objective evidence (linked to the National Institute for Standards and Technology) for the calibration of the instrument. ESSCO is an example of such a calibration house.

A calibration of an instrument is only as good as the organization that is performing it. You want to make sure it can be traced to NIST.

Uhhh, yes and no.

There is a loophole of sorts here. If the device that is distributing the air is flowing from a calibrated NIST traceable source then if the measuring device (ie, anometer) can replicate/agree with that device per spec you are all set; given your data and methods are recorded and repeatable.

For exampe

If I have, say, a calibrated MFC that is calibrated to xxx.xxx scfm through orifice diameter of zz then I can perform a comparative test with my non cal'd device given I match the calibration standards as determined by the standards group.

I know what I am trying to say, but it is quitting time and I am sick - so maybe more later.