How do I Tare the LVDT Connected to my Forney Test Pilot Display?

If you are having issues taring or zeroing the LVDT (Linear Variable Differential Transformer) on your Test Pilot Display, the problem may stem from one of two common causes:

1. The Test Pilot is not in the correct test mode.

2. The wrong LVDT calibration is selected.

Follow the steps below to ensure your setup is correct.

Step 1: Verify the Correct Test Mode (COMPRESSOMETER+)

The LVDT connected to the Strain 1 input only functions when the Test Pilot is set to the COMPRESSOMETER+ mode.

To select COMPRESSOMETER+ mode:

1. Press the button repeatedly until you see Run+ on the display.

2. Press the  button.

3. Press the  button again until you see COMPRESSOMETER+.

4. Press  to confirm.

5. Press  until you see Exit, then press .

You are now in COMPRESSOMETER+ mode.

Step 2: Check or Change the LVDT Calibration

If the LVDT still doesn’t work after selecting the correct test mode, it may be using an incorrect calibration profile.

The Test Pilot can store up to four LVDT calibrations for the Strain 1 input, labeled ‘a’, ‘b’, ‘c’, and ‘d’. Each calibration is associated with a gauge length. A gauge length of 0.000000 indicates no calibration exists for that profile.

To select a different LVDT1 calibration:

1. Navigate to the Strain 1 calibration selection:

   • Press the Calibration or Utility button (labeled depending on model).

   • Use the Up/Down arrows to cycle through the LVDT options: ‘a’, ‘b’, ‘c’, ‘d’. Then press to make your selection.

2. Press the 3/UTIL button to exit the menu and return to "live" mode.

Once you’ve selected a valid calibration, retry your test.