Core Solution: Gyro North-Seeker Method (Automated High-Precision)
This method uses Fiber Optic Gyroscope (FOG) or Ring Laser Gyro (RLG) to sense the Earth’s rotation rate components, and calculates the true north direction through multi-position sampling. Its advantages include full automation, strong environmental immunity, and simple operation, with accuracy better than 0.1° for standard models and up to arc-second level for high-end ones.
Equipment List
FOG/RLG north-seeker (with processing unit and display)
Industrial PC or data terminal (for parameter input and result readout)
Dedicated rigid fixture (to ensure the reference edge of the north-seeker is parallel to the turntable axis)
Operation Workflow (Three Steps)
Step 1: Coarse Alignment (Rough North-Seeking)
Mount the north-seeker rigidly on the turntable table via the fixture, ensuring its reference edge is strictly parallel to the turntable’s axis to be measured (zero line). After startup, the internal single-axis turntable automatically rotates to three specific positions approximately 120° apart, measures the Earth’s rotation rate components at each position, and calculates the approximate north direction.
Step 2: Fine Alignment (Precise North-Seeking)
Based on the coarse result, the internal turntable rotates to a position where the sensitive axis is approximately perpendicular to north (90° or 270°), and performs high-precision continuous sampling. The built-in algorithm automatically compensates for tilt angles (within ±7°~±20°) and external disturbances, finally outputting the precise angle between the reference edge and true north.
Step 3: Turntable Nulling to North
Input the output angle value into the turntable control system, or manually rotate the turntable table to null the reading. At this point, the turntable zero line precisely points to true north. Lock the turntable to complete the north-seeking procedure.
Step-by-Step Self-Operation Procedure (for Gyro North-Seeker)
Pre-Installation Preparation
1
Level the turntable: Use an electronic level to level the turntable, ensuring the tilt angle is within the north-seeker’s compensation range (typically ±7°~±20°).
2
Environmental check: Confirm there are no large ferromagnetic objects nearby (although FOG is resistant to magnetic interference, extreme strong magnetic fields may still affect accuracy).
Mounting the North-Seeker
Rigidly fix the north-seeker onto the turntable table via the dedicated fixture – no play allowed.
Adjust the orientation so that the reference edge of the north-seeker is strictly parallel to the turntable axis to be measured (zero line) – a dial gauge or square can assist calibration.
Keep absolutely stationary during measurement – any vibration will degrade sampling data.
Start North-Seeking
Power on the north-seeker, input the local latitude and longitude (some new models have built-in GPS for automatic acquisition; if not input, relative angle can still be measured but absolute accuracy degrades).
Select operation mode:
Fast mode: ~30 sec to 2 min, suitable for rapid on-site rough orientation;
High-precision mode: ~3~5 min, recommended for precise alignment before formal testing.
The device automatically completes the calculation and displays the angle between the reference edge and true north (with sign indicating rotation direction).
INulling the Turntable to
1
According to the out Northput angle, rotate the turntable table (manually or via control system) to null the current reading.
2
The turntable zero line now precisely points to true north.
3
Engage the mechanical locking device to complete north-seeking. Do not touch the table azimuth during subsequent tests.
Summary
The gyro north-seeker method, with its automation, high precision, and anti-interference features, has become the mainstream approach for modern turntable north-seeking. Following the standard workflow described herein – level → mount → static measurement → null & lock – a reliable north-seeking operation can be completed within 15 minutes. For applications demanding arc-second absolute accuracy, the theodolite-mirror method can be used as cross-verification. Remember: North-seeking is the “first button” of turntable testing – if the first button is wrong, all subsequent data are meaningless.
📩 For full specifications or to schedule a demonstration, please contact the Blue Equator technical sales team.
