Rate of flow

I am trying to monitor the rate of flow of a dry product by weighting it in a scale bucket. I understand that the formula for product flow is 1 hour * set point / seconds per weighted bucket. So to get a better and smother valve if I take 10 samples I would increase the formula to 10 hours instead of 1 hour. Is this correct?
36000000*7/(bw1+bw2+bw3+bw4+bw5+bw6+bw7+bw8+bw9+bw10)=flow rate.
I’m not an engineer; I’m a mechanic turn electrician turn programmer. That makes me very dangerous. A programmer with tools.
Thanks Pat
PS this is a compact controller L32E

Yes, you should get a smoother value (not "valve") if you calculate the mass flow from the weight of 10 buckets divided by the time for 10 buckets to flow past.

Nobody can answer your specifics because you don't define your variables, with UNITS. What is "setpoint"? Is bw1 the first bucket weight in lbm? Where does the 7 come from? No. of days in a week? If so, it would go in a formula as multiplier (7 day/wk). What does "36000000" represent? Is it related to conversion factor (3600 sec/hr) or maybe (3.6E6 ms/hr x 10)? What units do you want your flowrate in? lbm/wk?

I suggest you get a 1st year Physics book from the library and read the first few chapters on unit conversions, or try the web (wikipedia). In Physics and Engineering classes, if you give an answer on a test as "13.242" and the correct answer is "13.242 m/s", the professor usually writes "no units!, assumed furlongs/fortnight" and marks your answer wrong (I did). Do units matter? A very expensive spacecraft crashed into Mars several years ago and the cause was traced to "no units stated". A contractor reported the thrust value in Newtons, but NASA assumed the units were "lbf". Don't even get me started on the junk units used in the U.S. (BTU, lbm, lbf, ISP in "sec").

Do units matter? A contractor reported the thrust value in Newtons, but NASA assumed the units were "lbf".

Click to expand...

This was not a "units" problem, but a government incompetent-goof problem. I assume someone at NASA was fired for ASSUMing the incorrect units?

Your definitions sure help, but I can't relate exactly to the formula you give. It seems the dimensionally correct formula should be:

Flow Rate = (7 lbm/bucket)(10 bucket)/Ttot

where
Ttot = total time = bw1+bw2+bw3+bw4+bw5+bw6+bw7+bw8+bw9+bw10

If your times are in ms, your final flowrate has units of "lbm/ms". Note that the units come out algebraically and the (bucket/bucket) above divides out. If you want flowrate in other units, you multiply by a "unit conversion", like (3.6E6 ms/hr) to get "lbm/hr". If that is what you are trying to do, you have an extra factor of 10.

My suggestion to search the web was not for this particular formula, but for use of units in general. If you don't learn, then such tasks will prove endlessly confusing. Most people can handle a single conversion in their head, but try converting a value in "[(BTU/hr)*in]/[F*ft^2]" to "kW/(m*K)", which I recall are real units for thermal conductivity. MathCAD neatly handles this but is no longer affordable.

You will run into many "industry formulas" that have conversion factors buried within, leading to cryptic looking numbers. These should always state the assumed units for the input and output values, otherwise they are "junk equations". I recall the old book "Steam" by Babcock & Wilcox had many such formulas.

RocektTester Thank you for your reply.

The formula that I posted is simplified version; here is the entire rung from the program.
L1_RAW_FLOAT_4(9) = 7 lbs this is the target weight.
l1_ADR_RATE_IN(0) - (9) is the time between bucket drops.

This formula is supposed to give rate of flow over a one hour period.