Campbell Scientific CS110 Electric Field Meter - Manual (Page 21)

CS110 Electric Field Meter
of variations in surface cleanliness along with charging and discharging
processes. Polished 316-L stainless-steel is used for critical electrode surfaces
on the CS110 to minimize unwanted surface charges. CS110s with clean
electrodes have been found to display electric field offsets
<⏐30 V/m⏐, which
has negligible effect on the determination of M
parallel_plate
because of the ±15
kV/m range of electric fields used during factory calibration. Neglecting
O
parallel_plate
results in the simplified parallel-plate calibration equation
E = M
parallel_plate
⋅V (eq. 4).
The estimated measurement accuracy of M
parallel_plate
for the CS110 calibrated in
the parallel plate electric field calibrator illustrated in Figure 5 is ± 1 %. The
electric field offset of the CS110 can be measured by covering the stator with a
clean Zero Electric Field Cover (PN: 17642). If the resulting zero field reading
with the zero field cover exceeds an absolute value of 60 V/m then cleaning of
electrodes in the CS110 is suggested. The factory calibration data for a typical
CS110 factory calibration and resulting determination of M
parallel_plate
= 84.32
V/m ⋅mV (Volts/meter⋅millivolt) is illustrated in Figure 6.
y = 84.324x + 26.258
R 2 = 1
-15000
-10000
-5000
0
5000
10000
15000
20000
-200 -150 -100 -50 0 50 100 150 200 250
A
pplie
d Ele
c
tr
ic
Fie
ld (V/m
)
-20000
Charge Amplifier Output Voltage (mV)
FIGURE 6. Factory calibration data for CS110 SN: 1026
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