Plot/Test weight is off from bench standard

25 Feb 2010

There can be any number of reasons why your weights can appear to be off, and the reasons may vary depending on the combine and weigh system you are using. Here is what you should try for diagnosing where the problem is, and to provide helpful information when contacting Juniper Systems, Inc.

We recommend looking at the load cell voltage readings and weight readings. To do this complete the following steps:

1.  Turn on your HarvestData System.

2.  Turn on your Allegro if it does not automatically turn on when you turn on the SCCU.

3.  Navigate through the HarvestData software on your Allegro, from the Main Menu to Diagnostics then to Load Cell

4.  Confirm that the load cell voltage readings stay steady when the system is empty and running.

Example: The GrainGages total load cell reading should remain between +/- 0.5 of 0.8 Volts, or 800 mV.

5.  Write down the mV & weight readings, and fluctuation levels if any.

6.  Place a trial weight, equal to an average sample/plot weight, in the system. We recommend the following:





Between 4-5 lbs should be placed on the weigh pan over each individual load cell one at a time.

Bucket Systems

Between 20-25 lbs for plot weight. Between 3-4 lbs for test weight.


Note: We recommend keeping known weight items such as metal bar stock, or a bag/box of birdshot on-hand for future testing and calibration.

7.  Wait as the voltage increases to a certain point and stabilizes with the weight(s) placed in the system.

8. Record the readings and any fluctuations.

9. Repeat these steps with each load cell.

10. Remove the weight(s), and the system should return to the same voltage and weight readings as recorded before.

11. Review the load cell voltage and weight readings.

12. Check for any unusual readings from individual load cells.


If the problem is not apparent at this point, please contact Juniper Systems, Inc. at or call (435)753-1881.