Span test and adjustment

Follow the instructions below to perform a span-test for each SMA‑2-flat-ribbon sensor:

  1. Mount the reference plate to the SMA‑flat-ribbon sensor as shown in Figure 9: loosen the knurled bolts and attach the plates to the flat-ribbon.

    ATTENTION  Make sure the thickened edges of the SMA‑flat-ribbon are aligned along the grooves of the reference plate. Fasten the bolts by hand.

       

    Figure 9 Reference plate

  1. In the Commander open SMA, sensor table in the Technics menu.
  2. Click Test sensor. The SMA‑2 performs a measurement and displays the results in a pup-up window.

The C-values at both frequencies should increase by 70pF ±10 (i.e. reach 115pF ±10). The fraction of ice must remain at 0%!

If the C-values are outside these limits, perform a zero-adjustment and repeat the measurement with the reference plate. Should the C-values still deviate too much please contact Sommer Messtechnik.

NOTE  The measurement of the capacities with the reference plate is highly sensitive to the mounting of the plate and any interfering capacities SMA‑2, e.g. sensor cables.