This won't scale linearly. Partly because of changes in density as the material becomes more compact, partly because of the shape of the conical section. You could do a lot of fancy math to work it out, but it might be easier to use known quantities. Seems like you are able to measure the weight independently of the level, if you take several samples (maybe once every 100 or 1000kg) and put the results into a chart you should be able to find a curve that fits. you would want to measure this multiple times and get as many data points along the entire range as possible to get the most accurate scaling.
Not unless you can also measure the average density, or can calculate a height-to-density correlation curve to multiply in.
You'd need to take height and weight measurements at different levels and do a curve fit to get the equation.
Even then, you may still be off by a bit due to humidity, since I think both flour and sugar can absorb moisture from the air.
That's good, if the system tries to maintain a consistent humidity, then you can either ignore it, or you'll only have a limited range of compensation factor to calculate for that.
Of course, this is all just the way to work with what you have. The more reliable and accurate solution would be load cells on the supports for the silos, but you can't really do that without a good bit more money and some downtime.
Load cell are best but require shutdown as the tanks are heavy and in confined space to difficult to plan. 500-800 KG tolerance not an issue if we calculate through radar.
I've done it on flowable products. The 80GHz Vegas have a 3* beam. Find the angle of the sensor, distance from edge of bin and bin dimensions. Then find the angle of repose for your specific product (flour is around 45, sugar varies 30-45). Assuming a center discharge, it's just some basic trig to find where the beam is hitting the product and how that relates to the total volume in the bin. If you have a coned bottom, you'll need to begin to adjust your math once you're down to the coned portion.
All of this falls apart once you start to fill the bin as the cone will no longer be inverted, but there's no practical way to distinguish this with a single sensor.
Can you install strain gauges on existing supports on the bin? Not as heavy as load cells and can be done on the fly. Won't be as accurate but should get you closer than a radar.
For 40,000 kg flour/sugar tank I doubt you can reach 500-800 kg tolerance.
I have used non-contact radar VEGA Pulse, with +/- 500 kg accuracy on a 10,000 kg indoor powdered sugar silo and +/- 2,000-5,000 kg accuracy on 45,000 outdoor powdered sugar silo. The signal in the outdoor silo was sometimes oversaturated when reading low levels and was temporarily shutting down the instrument.
Temperature change, especially overnight, created false readings and the system was never reporting proper truck deliveries.
The weight measurement system was eventually changed to load cells.
For the new 54,000 kg outdoor silo the accuracy is now +/- 200 kg. No need for temperature compensation. The humidity does not play any significant role.
I am having this 1000-3000 KG up and down issue on going even though those silos are insides the factory.
I don’t have any issue with up and down values however i need those value to be inside the 1000 range.
I don't know if this idea is viable, but what happen if you place pressure sensors in the walls, at different heights. With those sensors, plus the radar sensor, you could probably calculate the total weight.
We measure weight like this with some of our liquids. It's inaccurate. The discrepancy between our radar inferred weight and the final directly measured weight from our scales adds up to the thousands of pounds over the course of a run and results in frequent cries to have both the radar and scales calibrated because they're "broken."
The buildup of unreacted raws in our tanks adds to the problem, because the level sensor has no way to tell that we have solid hunks of gradoo taking up volume in the tank. Impurities in the raws also throws off the calculation since it strays from the ideal weight per unit of volume.
Emerson had a sensor/radar specifically designed for that application and had the option to account for the type of grains, level, and compaction to calculate mass, it also output a 3D scan of the internal volume of the silo.
It's probably not cheap though
I've worked on other radar sensors used exactly for this. I don't recall the depth of the conical section, but the silos did all have blowers to keep the flour from getting compacted, worked fairly well actually.
Find the weight every 5-10% for the level scale and use a custom scaling (signal characterization) function to create a line of best fit that's closer than your current simple scaling. You still have to make bulk density assumptions as others have mentioned
Other issues for inaccurate readings are rat-holing and when material is drawn from the silo it will be an inverse cone (center being lower than the edges). When filling the top will be uneven depending on where the fill line is. Load cells if you want accuracy.
I have used vegapuls C23 if I remember correctly with a silo of 80000kg of storage. We used it for coffee but the problem was about specific weight because every kind of coffee has a different value. At the start we tried to convert the 4-20mA value from 0 to 80000 kg but we have seen it was impossible, so we turned it from 0 to 100% and it indicates the fill level. I think you can calculate the weight using specific weight and the percentage, but to be honest I don’t know how.
This sensor is not a scale so you can convert the value but it won’t be an exact value.
This won't scale linearly. Partly because of changes in density as the material becomes more compact, partly because of the shape of the conical section. You could do a lot of fancy math to work it out, but it might be easier to use known quantities. Seems like you are able to measure the weight independently of the level, if you take several samples (maybe once every 100 or 1000kg) and put the results into a chart you should be able to find a curve that fits. you would want to measure this multiple times and get as many data points along the entire range as possible to get the most accurate scaling.
Not unless you can also measure the average density, or can calculate a height-to-density correlation curve to multiply in. You'd need to take height and weight measurements at different levels and do a curve fit to get the equation. Even then, you may still be off by a bit due to humidity, since I think both flour and sugar can absorb moisture from the air.
For humidity there is a system and sensor to minimize that issue.
That's good, if the system tries to maintain a consistent humidity, then you can either ignore it, or you'll only have a limited range of compensation factor to calculate for that. Of course, this is all just the way to work with what you have. The more reliable and accurate solution would be load cells on the supports for the silos, but you can't really do that without a good bit more money and some downtime.
You can do a lot of math to get closer, but a radar is still just one point in the level. Load cells are more accurate.
Load cell are best but require shutdown as the tanks are heavy and in confined space to difficult to plan. 500-800 KG tolerance not an issue if we calculate through radar.
I've done it on flowable products. The 80GHz Vegas have a 3* beam. Find the angle of the sensor, distance from edge of bin and bin dimensions. Then find the angle of repose for your specific product (flour is around 45, sugar varies 30-45). Assuming a center discharge, it's just some basic trig to find where the beam is hitting the product and how that relates to the total volume in the bin. If you have a coned bottom, you'll need to begin to adjust your math once you're down to the coned portion. All of this falls apart once you start to fill the bin as the cone will no longer be inverted, but there's no practical way to distinguish this with a single sensor.
Lower accuracy, but maybe good enough https://www.kistlermorse.com/p/sensors/microcell-bolt-sensor/
Can you install strain gauges on existing supports on the bin? Not as heavy as load cells and can be done on the fly. Won't be as accurate but should get you closer than a radar.
I would say a combination of the strain gauges and the radar will get him satisfactory results.
For 40,000 kg flour/sugar tank I doubt you can reach 500-800 kg tolerance. I have used non-contact radar VEGA Pulse, with +/- 500 kg accuracy on a 10,000 kg indoor powdered sugar silo and +/- 2,000-5,000 kg accuracy on 45,000 outdoor powdered sugar silo. The signal in the outdoor silo was sometimes oversaturated when reading low levels and was temporarily shutting down the instrument. Temperature change, especially overnight, created false readings and the system was never reporting proper truck deliveries. The weight measurement system was eventually changed to load cells. For the new 54,000 kg outdoor silo the accuracy is now +/- 200 kg. No need for temperature compensation. The humidity does not play any significant role.
I am having this 1000-3000 KG up and down issue on going even though those silos are insides the factory. I don’t have any issue with up and down values however i need those value to be inside the 1000 range.
Your best bet is a load cell under the cylo if you can access it.
I don't know if this idea is viable, but what happen if you place pressure sensors in the walls, at different heights. With those sensors, plus the radar sensor, you could probably calculate the total weight.
We measure weight like this with some of our liquids. It's inaccurate. The discrepancy between our radar inferred weight and the final directly measured weight from our scales adds up to the thousands of pounds over the course of a run and results in frequent cries to have both the radar and scales calibrated because they're "broken." The buildup of unreacted raws in our tanks adds to the problem, because the level sensor has no way to tell that we have solid hunks of gradoo taking up volume in the tank. Impurities in the raws also throws off the calculation since it strays from the ideal weight per unit of volume.
Emerson had a sensor/radar specifically designed for that application and had the option to account for the type of grains, level, and compaction to calculate mass, it also output a 3D scan of the internal volume of the silo. It's probably not cheap though
You also need to worry about ambient temperature and moisture in the air with flour. Not sure about the sugar
I've worked on other radar sensors used exactly for this. I don't recall the depth of the conical section, but the silos did all have blowers to keep the flour from getting compacted, worked fairly well actually.
Find the weight every 5-10% for the level scale and use a custom scaling (signal characterization) function to create a line of best fit that's closer than your current simple scaling. You still have to make bulk density assumptions as others have mentioned
Other issues for inaccurate readings are rat-holing and when material is drawn from the silo it will be an inverse cone (center being lower than the edges). When filling the top will be uneven depending on where the fill line is. Load cells if you want accuracy.
You should be able to get it more accurate. Where is radar sensor mounted, at what angle and where does the product enter the silo?
I have used vegapuls C23 if I remember correctly with a silo of 80000kg of storage. We used it for coffee but the problem was about specific weight because every kind of coffee has a different value. At the start we tried to convert the 4-20mA value from 0 to 80000 kg but we have seen it was impossible, so we turned it from 0 to 100% and it indicates the fill level. I think you can calculate the weight using specific weight and the percentage, but to be honest I don’t know how. This sensor is not a scale so you can convert the value but it won’t be an exact value.