Geosense HLC 6000 Series, Instruction Manual

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15
V1.0 July 2020
.
6.3 Data Reduction
6.3.1 Overview
Readings from a Vibrating Wire Transducer are in a form that is a function of frequency, ra-
ther than in units of pressure. Commonly the units would be either Frequency
-
Hz, Linear
B Digits
-
Hz
2
/1000 or Hz
2
/1000000 Linear B Digits are required for all calculations.
To convert the readings to units of pressure some calculation is required. Calibration factors
must be applied to the recorded values. For most Vibrating Wire sensors, these factors are
unique and are detailed on the individual sensor calibration sheets. A unique calibration
sheet is supplied with every Geosense
®
Vibrating Wire Transducer.
If the readout displays ‘ Frequency ’ values, (e.g. 2768.5 Hz) only a simple calculation is re-
quired to convert the readings to Linear Digits.
Linear Digits (Hz
2
/1000) = ( 2768.5 )
2
/ 1000
= 7664.6
Certain data loggers store their Vibrating Wire data in Linear Digits but further divided by
1000. In this case the data would have to be multiplied by a further 1000 to maintain the
standard Linear Digits (Hz
2
/1000) format for standard calculations.
The first step to producing an engineering value is to convert the reading to Linear Digits
(Hz
2
/1000). An example of this calculation can be seen on the next page.
(1) Readout Display = 0.03612
Linear Digits (Hz
2
/1000) = ( 1 / 0.03612 x 10
– 2
)
2
/ 1000
= 7664.8
(2) Readout Display = 3612
Linear Digits (Hz
2
/1000) = ( 1 / 3612 x 10
– 7
)
2
/ 1000
= 7664.8