MSP430FR6047: The effect of air bubbles on flow measurement

Hi Cherry,

A small bubble on the transducer will not cause much difference on the signal. Unless, the air bubble is big enough to cover the entire transducer surface..

Best regards,

Cash Hao

Hi Cash,

Thanks! I just hear back from the customer today.

If the bubble cover the whole surface of  transducer, it will report empty? If small bubbles are attached, does it cause a large deviation in the flight time of both the downstream and the reverse currents? For example, a false image of large traffic will occur at a static level.

Thanks and Best Regards,

Cherry

Hi Cherry,

Cherry Zhou said:

If the bubble cover the whole surface of  transducer, it will report empty?

It will most likely to report "no signal was detected on UPS and DNS channel"

Cherry Zhou said:

If small bubbles are attached, does it cause a large deviation in the flight time of both the downstream and the reverse currents? For example, a false image of large traffic will occur at a static level.

It may cause cycle slips. In this condition, the customer will need to filter out these bad data before they calculate the flow rate.

Best regards,

Cash Hao

Hello Cash,

Cash Hao11 said:

It may cause cycle slips.

How to tell whether they have entered cycle slips, and what is the difference between totalTOF_UPS or totalTOF_DNS and normal state in this state?

Thanks and regards,

Cherry

Hi,

May I know is there any updates regarding the last response? Thanks.

Best Regards, 

Cherry

Hi Cherry,

A cycle slip means that the calculated time of flight miss around one cycle away from the actual time of flight. One cycle depends on the frequency of the transducer. If the transducer is 1MHz, then one period is 1us.

Best regards,

Cash Hao