Vibrating Wire Measurements; Vspect - Campbell CR300 Series Product Manual

For example, if a flow sensor outputs 4.5 pulses per second and you use a 1 second scan, one
scan will have 4 pulses and the next 5 pulses. Scan to scan, the flow number will bounce back
and forth. If you did a 10 second scan (or saved a total to a 10 second table), you would get 45
pulses. The total is 45 pulses for every 10 seconds. An average will correctly show 4.5 pulses per
second. You wouldn't see the reading bounce on the longer time interval.

14.6 Vibrating wire measurements

The data logger can measure vibrating wire sensors through vibrating-wire interface modules.
Vibrating wire sensors are the sensor of choice in many environmental and industrial applications
that need sensor stability over very long periods, such as years or even decades. A thermistor
included in most sensors can be measured to compensate for temperature errors.
14.6.1 VSPECT®
Measuring the resonant frequency by means of period averaging is the classic technique, but
Campbell Scientific has developed static and dynamic spectral-analysis techniques (VSPECT) that
produce superior noise rejection, higher resolution, diagnostic data, and, in the case of dynamic
VSPECT, measurements up to 333.3 Hz. For detailed information on VSPECT, see Vibrating Wire
Spectral Analysis Technology.
14. Measurements 84