Campbell CR3000 Micrologger, Руководство оператора

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Section 5. Overview
74
5.2.2.4 Strain Measurements — Overview
Related Topics:
• Strain Measurements — Overview
(p. 74)
• Strain Measurements — Details
(p. 378)
• FieldCalStrain() Examples
(p. 243)
Strain gage measurements are usually associated with structural-stress analysis.
5.2.3 Pulse Measurements — Overview
Related Topics:
• Pulse Measurements — Specifications
• Pulse Measurements — Overview
(p. 74)
• Pulse Measurements — Details
(p. 404)
The output signal generated by a pulse sensor is a series of voltage waves. The
sensor couples its output signal to the measured phenomenon by modulating wave
frequency. The CR3000 detects the state transition as each wave varies between
voltage extremes (high-to-low or low-to-high). Measurements are processed and
presented as counts, frequency, or timing data.
P terminals are configurable for pulse input to measure counts or frequency from
the following signal types:
•
High-frequency 5 Vdc square-wave
•
Switch closure
•
Low-level ac
C terminals configurable for input for the following:
•
State
•
Edge counting
•
Edge timing
Note A period-averaging sensor has a frequency output, but it is
connected to a SE terminal configured for period-average input and
measured with the PeriodAverage() instruction. See Period Averaging
— Overview
(p. 76).
5.2.3.1 Pulses Measured
The CR3000 measures three types of pulse outputs, which are illustrated in the
figure Pulse Sensor Output Signal Types
(p. 75).