The output of the 6180 Inclinometer Sensor is a corrected angle of inclination. The standard sensor has a full range of ±90° and a calibrated range of ±30°. Register values for the Gauge Factor and Offset are factory-written to the Modbus registers for each sensor using calibration data.
The lateral displacement (D) of the wheel-end of any sensor relative to the vertical line running through the receiver-end of the sensor is equal to:
D = Lsinq
equation 1: Sensor Displacement
Where:
L = The length of the sensor
q = Inclination angle of the sensor, as described above
The profile of the borehole is constructed by using the cumulative sum of these displacements starting with the terminal sensor. For instance, refer to the figure below.
22:
Figure 22: Deflection Intervals
The total displacement of the wheel-end of the outermost sensor from the vertical line drawn through the end of the innermost sensor is:
Dtotal = L1sinq1 + L2sinq2 + L3sinq3
equation 2: Total Displacement
In a given installation, temperature effects can cause real changes of tilt; therefore, each sensor is equipped with a device for measuring the sensor temperature. This enables temperature-induced changes in inclination to be distinguished from inclination due to other sources.
An important point to note is that sudden changes in temperature will cause both the structure and the sensor to undergo transitory physical changes, which will show up in the readings. The sensor temperature should always be recorded, and efforts should be made to obtain readings when the instrument and structure are at thermal equilibrium. The best time for this tends to be in the late evening or early morning hours.
Since the purpose of the inclinometer installation is to monitor site conditions, factors that may affect these conditions should be observed and recorded. Seemingly minor effects may have real influence on the behavior of the structure being monitored and may give an early indication of potential problems. Some of these factors include, but are not limited to, blasting, rainfall, tidal or reservoir levels, excavation and fill levels and sequences, traffic, temperature and barometric changes, changes in personnel, nearby construction activities, seasonal changes, etc.