Campbell Scientific CS110 Electric Field Meter - Manual (Page 22)

CS110 Electric Field Meter
FIGURE 7. NIST calibration certificate
Careful removal and replacement of the stator on the CS110 does
not invalidate the factory derived M
parallel_plate
of a given unit.
However, switching stators with another unit or accidentally
bending the stator, shutter or sense electrodes invalidates the
factory parallel-plate calibration because of possible electrode
dimensional changes.
NOTE
5.2 Site Correction
As previously mentioned, each CS110 is factory calibrated in a parallel plate
calibration fixture resulting in calibration equation 4. However, when
monitoring the Earth’s electric field, equation 4 is valid only if the instrument
aperture is mounted flush with the Earth’s surface and upward-facing. Yet for
permanent outdoor measurements of electric field, a flush-mounted and
upward-facing orientation is problematic because of dirt, bird droppings, rain,
etc., collecting on the sense electrodes and fouling the measurement.
14