Campbell Scientific CS110 Electric Field Meter - Manual (Page 45)

CS110 Electric Field Meter
±4.2 nA. Leakage current values in excess of ±4.2 nA can cause measurement
errors and are indicated by status = 11.
Cleaning of the CS110 electrodes and/or insulators is recommended if any
of the following conditions occur:
• When insulators are dry, and leakage current exceeds ± 4.2 nA as indicated
by status = 11.
• Visual evidence of contamination (salt deposits, scaling, dust, spider webs
etc.) on or around electrode area.
• Zero field reading with Zero Electric Field Cover (PN: 17642) exceeds
± 60 V/m. Note: it is important that the inside of the zero field cover also
be clean for good zero field reading.
Electrode Cleaning Procedure:
1. Remove the stator by loosening the 2 Philips head screws on the motor
assembly base plate, allowing the stator to pivot and be removed.
2. Inspect the stator for any contaminant deposits and scrub such deposits off
with soap and hot water if available. Any residue may form non-
conductive layers that can hold unwanted surface charge. Using a brush
that will fit between the shutter and the sense electrode, carefully wash the
shutter and sense electrode, along with the three insulators attaching the
sense electrode to the main body of the CS110. One brush (CSI PN
17578) ships with each CS1110. Large offsets are likely due to electrical
charges residing insulative deposits on metallic surfaces, while large
leakage currents are likely due to contaminated insulators.
3. Rinse well, using de-ionized water if available, and blow dry with air.
Note: Rubbing and wiping tends to induce unwanted surface charging
that will eventually dissipate.
4. Reassemble the stator making sure it is positioned properly before
tightening the two Philips head stator screws. Try and avoid getting
fingerprints, etc. on clean electrodes as they can result in unwanted surface
charge. (Clean cotton gloves are helpful.)
5. Attach the zero field cover plate (PN: 17642) to the stator and verify that
the leakage current ≤ ⎢0.5 nA⎟ and that the zero field offset ≤ 60 V/m.
Leakage current > ⎢0.5 nA⎟ and/or zero field offsets > 60 V/m indicate
problems with cleanliness and/or unwanted surface charge.
10.5 Changing Desiccant
The CS110 is shipped with desiccant inside the sealed case to reduce humidity
for the sensitive electronics enclosed. A humidity sensor is also contained
inside the CS110 case to allow monitoring of the internal relative humidity.
The following CRBasic instruction provides internal humidity data to the
variable Internal_RH, which can be included in an output table.
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