Traffic measurement issue, seeking help

Flowmeters with a large range have relatively poor accuracy when the flow rate is low

This will require spending money; take a look at the top international products – they might be suitable

There are some things for which there’s no need to turn to foreigners or Er Gouzi; a foreign-made ball isn’t square or rectangular, nor does it have triangular edges or pulleys, right? :P: There are some things that foreigners can’t handle, so they ask us to develop instruments for them. If you’re facing difficulties, come and ask me. Maybe there’s a ready-made watch hidden in my pigpen; you can buy one and take advantage of this deal, and that way you’ll be able to turn misfortune into good fortune. Brother’s ideas are often bizarre, unique, and highly effective; they usually don’t cost much either, and they generally can’t kill anyone. Once you fully understand the principles of flow measurement, as the original poster mentioned, then it shouldn’t be that difficult, right? Bro thinks it’s not a difficult task. The flow meter used in conjunction with nozzles – I received orders to develop such a product back in 2009. Wild boars live in the deep mountains of the Qinling Range; I created a cover for the instruction manual so that people could take a look at it.

Friendly reminder: Brother Nozzle can’t manufacture them; he’s just a watch maker who produces and sells watches on his own. Who manufactured the nozzle used by the poster? Who made it? He should provide the relevant parameters, right? Post the parameters for the 10 nozzles; once I’ve seen them, we can discuss it. I also need to explain how to replace these 10 nozzles. That is, to clarify the process operation steps.

I remember there are differential pressure flowmeters with two ranges – one transmitter for low flow rates and another for high flow rates; the original poster might want to take a look

It’s for experiments, not for industrial use. The nozzles need to be manufactured manually; the minimum diameter is 0.5 mm, the maximum diameter is 5 mm, with a nozzle being fabricated every 0.5 mm in between. Regardless of the nozzle, the maximum flow rate is 40 m/s; this range is too wide. I just came up with a method, but I’m not sure how large the error will be: when the flow rate in the main channel is low, a secondary channel can be used, such as a nozzle with a constant diameter of 2.5 mm. This way, the overall range of flow rates is not as wide. When using a nozzle with a minimum diameter of 0.5 mm in the main channel, the flow rate can be calculated based on the ratio of the exit areas. However, due to differences in frictional losses along the path, there is concern that the error might be relatively large……

The range ratio is too large, making it difficult to choose a flow meter; if the requirements are not high, a rotameter would be a good choice

　　It seems like the poster is conducting some kind of experiment. 　　Since it’s an experiment, things can be carried out in stages, and there’s no need to use a flow meter. Moreover, even flowmeters with such a large range ratio don’t offer much better accuracy. When using methods such as shunting to measure flow rate, the introduction error of the system is also significant. 　　The flow rate can be calculated by measuring the volume or weight of the water exiting the end of the pipe over a certain period of time; experimental data is then collected once the flow rate meets the required standards. 　　For example: use a digital scale to measure the weight of the water, calculate in advance the time required for the scale to display n numbers at the desired flow rate, and make a few adjustments until the flow rate meets the requirements.