This article refers to the original version of the Force Plate (FP-BTA) (those purchased prior to November 10, 2023). Refer to the video below to determine if this is relevant to your force plate.
You will need to confirm with Vernier Technical Support that replacing the load cells is the correct course of action. Load cells may need to be replaced if they experience hysteresis or in some cases connection pins rattle loose during shipping.
If you are willing to replace the load cells yourself using replacements from Vernier, follow these instructions. In the discussion with Technical Support you may be asked to remove the cover and check the wire connections. Caution: The connectors on the load cells are a weak spot; do not pull the plugs off by the wires. First try wiggling the wires and see if the readings change; you may just have a bad connection at this plug.
Note that load cells are typically replaced in matched pairs. Do not replace a single load cell unless its number matches the other load cell in the force plate.
You will need: a Phillips screwdriver, an adjustable torque driver with a 1/8 inch hex bit, replacement load cell(s), and electrical tape.
First, unscrew the bottom six screws, as shown in the video below. Then use the adjustable torque driver at maximum torque to remove the 8 top screws. Important: if you do not use an adjustable torque driver you are likely to strip the screws. Open the Force Plate by removing the top. Remove the load cells. One at a time, hold each load cell in place as you attach it loosely to the bottom of the Force Plate. Be sure to leave the screws a bit loose, which will help when attaching the top plate.
Carefully attach the load cell wires to the circuit board as shown in the video. Tape down the wires to avoid pinching them during reassembly or later use. While you are inside the force plate, make sure the circuit board screws are snug. They have been known to come loose.
Once you have replaced the load cell(s), use the adjustable torque driver set to half the maximum torque to screw the top back on with the hex screws. Finally, tighten the bottom screws.
After reassembling the force plate, recalibrate the force plate using a 2-point calibration and a known weight. The bigger the weight, the better the calibration will be. Be sure to calibrate both ranges.
For additional assistance and questions, contact Vernier Technical Support at physics@vernier.com, 888-837-6437, or via the chat function on vernier.com.
Related entries:
Force Plate Troubleshooting and FAQs
How do I replace the cable on an original style Force Plate?