VERIFICATION OF YIELD MONITOR PERFORMANCE FOR ON-THE-GO MEASUREMENT OF YIELD WITH AN IN-BOARD ELECTRONIC SCALE
A commercial combine equipped with a yield monitor and Global Positioning System (DGPS) was constructed 
to include a weighing system in the clean grain tank. The scale was able to output its current readings two times per 
second to a data-logger. The reading from the yield monitor and the scale could be matched to check the accuracy of the 
yield monitor summary as well as the individual (1 s) readings. Harvest data from fields of corn and oats were collected 
using this system. Data from both the scale and yield monitor were analyzed to verify the accuracy of the yield monitor. 
The scale was verified to be accurate by calibration. Results showed that the yield monitor has two data processing 
streams; one gives the individual weights (1 s interval weights) and the other gives the summary weights (total load 
weights). The results showed that these two streams are slightly different. Further analysis was conducted to understand 
these differences. The results showed an increase in the yield monitor accuracy with the harvest strip length. Data 
collected in 1997 were more accurate than data collected in 1996. It was concluded that improvement was primarily due 
to the updated yield monitor system (ver. 6.02 CJC).