KA800M Magnetic Scale
2 Features and Specifications
KA800M magnetic scale is a non-contact displacement measurement system, using detection
of magnetic signals, which features:
- High precision of up to ± 10µm / 300mm or ± 20µm / 1000mm,
- Measurement length of up to 3–100m,
- Low sensitivity to impact, vibration and contamination (e.g. dirt and petroleum),
- ease of maintenance due to high resistance to wear, and
- Robustness.
Specifications:
- Resolution: 1µm
- Output signal: RS422
- Operating voltage: 5V±5%
- Max. moving speed: 30m/min
- Operating temperature: -20–70℃
3 Principle of Operation
The read head is fixed on a part of the lathe, and does not move. When the KA800M body is
connected to the moving part of the lathe, the tape on the body records an alternating
magnetic field with north and south poles, while the two increment sensors of magnetic head
on the read head measures the alternating magnetic field.
Since the tape is not in contact with the magnetic head, the two increment sensors on the
entire magnetic head must be always located above the tape, which pick up the period of the
alternating magnetic field so that the controller can determine the distance. In order to
determine the direction of movement, an offset exists between these two increment sensors,
and the sine output signals of the sensors have a phase shift of 90°, which can be considered
as a sine and cosine signals. Both the signals are converted into A/B pulses by the magnetic
head, which is then sent to the controller (RS422) to generate differential signals. A phase
shift exists between the A and the B digital signals shifting periodically, so as to determine
the direction of sensor.
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