For combines with a mass flow sensor (usually at the top of the clean grain elevator):
- Look for wear on the flow sensor’s impact or deflector plate. Replace the plate if worn or damaged.
- Look for excessive wear on the grain elevator and missing or worn paddles.
- Check the spacing between the paddles and the top of the elevator. Verify that it meets the manufacturer’s requirements.
- Make sure the clean grain elevator chain is tightened to manufacturer specifications.
For combines with an optical sensor (mounted on the side of the clean grain elevator):
- Make sure the sensors are clean and undamaged.
- Ensure the clean grain elevator paddles are not rubbing against sensors.
- If purchasing a combine, whether new or used, with an existing yield monitoring system, check for proper installation. Verify that the mass flow sensor is mounted securely. If using a grain cart with scales or a weigh wagon to weigh grain harvested for yield monitor calibration loads, check that they give accurate weight data. Check weigh wagon weights against certified scales each season to ensure the load estimates are within a few percent. Use the same scales throughout calibration.
If you aren’t sure of the accuracy of your grain moisture meter, take it to a local grain elevator with a federally approved moisture meter. Compare estimates on grain samples with a wide range of grain moisture content, such as 13 to 28 percent. Document differences between your meter and meters known to be accurate.
Source: missouri.edu