Why is my C2® calibration incorrect?

On the Hardy units, C2® Second Generation calibration uses test data to establish a counts per engineering units ratio. This data was determined during the testing of each Hardy load point. During testing all load points are installed on a level surface with the load applied directly on the load point without any side load. It is important you duplicate these conditions on your scale installation. This extra attention to detail will result in a very reliable and accurate scale system. The accuracy of your scale is the sum of the mechanical and electrical errors.

If you use a summing board with trim pots or potentiometers you cannot perform an accurate C2® calibration as the added resistance will change the sensitivity of your load cell, causing inaccurate weight readings.

If your C2® calibration is incorrect you should check the following:

1. Wiring is the most common error and can appear as an error code during calibration, poor weight reading, or an instrument locked on HARDY.
     a) Verify the color code and order of termination. Consult the installation manual, data sheets, drawings and look for      color code labels on the load point cable.
     b) When landing wires, insure the bare wire and not the insulation is being secured.
     c) Reversed polarity of any C2+ GRAY or C2- VIOLET wires will show number of C2 chips found as 0.  If one of the C2 chips is shorted, a number of C2 chip read equals 9.  Verify the polarity at the back of the scale and in the summing junction box.
     d) When using the IT summing junction box. The C2® wires must be installed from the weight controller. This communicates the IT functions and results to and from the controller. Without the C2® wires attached all the relays will activate giving and indication of no weight or millivolt change.  This even if you are not using the Hardy C2 load Points.
     e) Verify the load point polarity is correct. Most load point assemblies can be installed upside down. This will produce a negative signal output and the outputs will mathematically add incorrectly.
     f) If you must splice or have an intermediate termination, use the same wire colors from start to finish.
     g) Examine the cable for damage from impact. The outside of the cable may only seem dented, but the wires inside could be damaged. Load point cable should not be spliced or cut.
     h) Ensure you are using Hardy C2 cable.  (see attached).

2. Electrical
     a) Verify each load point is registering a proper millivolt signal. Use Integrated Technician ®, or a good multi-meter.
     b) Verify the millivolt signal for each load point responses in an equal and positive direction.
     c) Apply a test weight to a load point and verify you are seeing the correct weight. Move the test weight to the next load point and verify the correct weight. Differences of more than 5% indicate a problem.
     d) You may need to shim or adjust the load point height to see the signal. The signal levels will differ slightly. Adjust for a level and balanced scale. The weight of different mechanical systems will influence the millivolt signal level.
     e) If no millivolt response, refer to step #1 on wiring, or verify the strain gauge validity with an ohmmeter.

3. Mechanical problems will appear as slow weight response, incorrect weight, unstable weight, or no weight response.
     a) Verify all pipes and conduit attached to the scale are flexible and not applying any unwanted force.
     b) If you can shake