Campbell Scientific CS110 Electric Field Meter - Manual (Page 11)

CS110 Electric Field Meter
1.5 Digital I/O
Three general purpose 0 to 5 V digital I/O lines are available on the CS110
Power cable (CS110CBL3-L) that attaches to the circular power connector on
the underside of the CS110. The blue, yellow, and green wires connect to
control ports C1, C2, and C3 respectively. Using CRBasic, these digital I/O
lines can be used to conditionally turn on alarms, provide an interrupt or pulsed
signal to be measured by the CS110, or as a serial communication port.
1.6 Self-Check Features
The CS110 has been designed to provide reliable electric field measurements
and to minimize and simplify maintenance. The CS110 incorporates extensive
self-checking for each measurement in an effort to identify measurement
problems and reduce or eliminate scheduled maintenance. The status code
returned from each electric field measurement reports on instrument health
along with any measurement problems as described in Appendix A.
For example, insulator leakage current is measured during each electric field
measurement, indicating the cleanliness of electrode insulators. A leakage
current compensation circuit for the charge amplifier input is incorporated in
the CS110 to minimize the effects of insulator leakage current on measured
results (Patent pending). A status code indicating excessive leakage current is
returned if the measured input leakage current exceeds the compensation range
due to insulator cleanliness problems.
A relative humidity sensor is included inside the CS110 case to provide
information on when case desiccant should be changed. The CS110 also
provides measurement of the battery input voltage in order to monitor the input
power to the instrument. Section 7 discusses CS110 electric field measurement
details. CS110 maintenance details are discussed in Section 10.
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