FSO online grain moisture measuring system in the bypass

Grain moisture measured in the flow, with no sample taken

A mill, a dryer or an intake point judges a batch from a sample: somebody goes for the grain, carries it to the meter and writes the reading down. A quarter of an hour or an hour passes between one sample and the next, and the moisture of the flow moves in the meantime - another batch, another place in the heap, another stage of drying.

The FSO sits in a bypass loop beside the main flow and measures by itself. It takes a portion of grain, weighs it, measures water content and temperature, empties the chamber and starts again. The reading goes to the display and to the current outputs, so it can feed the dryer control or the intake documentation without an operator.

How the bypass loop works

Part of the flow passes through the measuring chamber while the rest carries on its way. One portion is about 800 ml, a measurement takes 15 seconds, and the flow through the chamber reaches 3.2 l/min. Emptying the chamber needs compressed air: a Ø4 mm connection at 5 bar ±0.5 bar. How the system is tied into the plant is worked out individually, to fit the existing installation; the manufacturer supplies an installation diagram.

Three quantities from one measurement

Water content is measured by a high-frequency capacitive method. At the same time the integrated scale gives the hectoliter weight and compensates the bulk density, and an infrared sensor measures the grain temperature and compensates its effect on the reading. Calibration accuracy is ±0.4 % water content, and the display resolution 0.01 %.

Calibration curves

The system arrives ready to work, with every calibration curve common in Europe stored: maize, rye, triticale, wheat, durum wheat, peeled buckwheat, spelt, peeled and unpeeled millet, sorghum millet, barley, oats, rape, soybeans, horse beans, sunflower seeds, pumpkin seeds, rice, field peas and linseed. A curve for a material outside that list is worked out in the manufacturer’s laboratory, and an existing one can be adapted to a particular grain.

Operation on the spot and from the control room

The device carries a 7 inch colour touch display, with menus in English, German, Italian, French, Spanish, Portuguese, Slovenian, Hungarian, Polish, Romanian and Russian. The optional Ethernet interface mirrors the operating screen on a computer in the same network, so the system can be run from a control station. The REST interface returns the last measurement, or the whole set of them, as JSON over HTTP on port 8081.

Signals for control and for documentation

Moisture goes out on a 4-20 mA output scaled 0 to 50 %, temperature on a second 4-20 mA output covering 0 to 60 °C; an output for the hectoliter weight is available as an option. A 24 VDC relay handles alarm functions defined for the particular plant, and a thermal or a label printer can be connected for printed records.

Advantages measurement in the flow, with no samples to take and carry water content, hectoliter weight and grain temperature from one run a reading every few seconds instead of once a quarter of an hour analogue and digital outputs for dryer control and for recording operated on the spot from the touch panel or remotely from a computer European calibration curves stored, unusual ones made to order 10 years of repair warranty and manufacturer support

Technical data

Accessories

• Art. no. 14092 - alarm function, 24 VDC relay for warning devices; thresholds defined for the particular plant
• Art. no. 14097 - Ethernet interface, mirrors the operating screen on a computer in the same network
• Art. no. 14091 - REST interface, HTTP on port 8081, the last measurement or the whole set as JSON
• Art. no. 14093 - analogue outputs for moisture and temperature, optionally for the hectoliter weight as well
• Art. no. 14094 - connection of the FSO to an existing plant system
• Art. no. 14096 - grain pre-cleaning unit, filtering foreign bodies out of the stream so they neither falsify the reading nor block the chamber
• Art. no. 14095 - data printer, thermal or label

The FSO is built for a particular installation, so the set of options, the way it is tied in and the item numbers are confirmed with the manufacturer before the order.

FSO or FSA

Both instruments measure fully automatically and both give the hectoliter weight and the sample temperature. What separates them is where they work. The FSA stands on a bench at the intake point and measures the sample somebody brings to it. The FSO stands at the installation and measures by itself, without interruption. For checking deliveries the FSA is enough; for running the drying and documenting quality continuously, the FSO.