Plant - Finding and Storing Load Cell Ratings (Sensitivity / Rated Capacity)
Finding Load Cell Ratings
All load cells used for a weight channel MUST have identical ratios of sensitivity to capacity (sensitivity/capacity). This is true if all load cells are of the same model and should be checked otherwise.
Using the calibration number from an existing indicator:
Find and note the calibration number of your existing indicator as the Rated Capacity (lb), and use 0.40 mV/V as the Sensitivity. Please consult the existing indicator's user manual for help retrieving the calibration number. Go to Storing Load Cell Ratings.
In all other cases:
Read and note the Sensitivity (Rated Output) and Rated Capacity (Rated Load) from any one load cell on each weight channel. Multiply the Rated Capacity by the TOTAL number of load cells connected to the weight channel.
Storing Load Cell Ratings
- Ensure the Libra Plant device and app are paired and connected.
- Ensure units (lb, kg) are set to those of the Rated Capacity found previously.
- Select the Devices tab. Insure any used weight channels are set to "On." If only using one weight channel, ensure the unused channel is set to “Off.”
- Enter the Sensitivity and Rated Capacity noted previously by tapping on the appropriate weight channel's blue Sensitivity or Capacity number, tap Next, then Save.
- Tap the blue Calibration number. Enter the Calibration Factor as 1.0, if it's not set at 1.0 already, tap Next, then Save.
- Select the Device tab, ensure the container is empty, Zero Scale and confirm.
- Select the Display tab and tap Tare.
- Apply a known weight (perhaps your body weight) to one of the channel's load cells, noting the displayed weight. Repeat with each remaining load cell. If the load cells agree and are roughly correct, you can now calibrate. If the load cells agree but are roughly half of that expected, double the Rated Capacity entered previously. If weights do not agree, check wiring and load cell orientation.