Magnetic Scale Read Head — Common Issues

The magnetic scale is based on a recording method similar to audio recording, where the read head records strictly spaced magnetic waves on the scale (or disk). The magnetized scale that records these waves is called a magnetic scale. The distance between adjacent grating waves is the grating wavelength or pitch. What issues may arise when using a magnetic scale?

When the magnetic scale starts and shows no response and the unit/country indicator lights are off, possible causes include:

1) Power cable not connected, loose connection, or blown fuse.

2) The magnetic scale fuse may be blown.

Like a sliding potentiometer, the magnetic scale operates as a voltage divider and uses relative voltage to display measured position. Therefore it requires:

1. Stable supply voltage.

Industrial supply needs a reference voltage (e.g., 5V) with stability within ±0.1% and allowable fluctuation around ±0.01V; otherwise display fluctuations will occur. If display fluctuations are within the supply voltage variation range, the electronic scale is considered normal.

2. Adequate power capacity.

If the power capacity is insufficient, display jitter may occur during movements such as mold closing or injection. Especially when electromagnetic valve drive and the scale share power, voltage fluctuations can be measured with a multimeter. If static and RF interference and poor alignment are excluded, suspect insufficient power capacity.

3. Static and RF interference can easily cause display jitter.

Signal and power lines should be routed separately. The electronic scale should use a forced grounding bracket and the magnetic scale housing (measured resistance between cover screw and bracket should be <1Ω) should be well grounded. Use shielded signal cables and ground the shield at one end in the control cabinet. For static interference, temporarily shorting the cover screw to a machine metal point can eliminate the issue; RF interference is harder to fix and may be caused by robots or variable frequency drives.

4. Proper alignment.

Allowable angular error is ±12°, parallelism ±0.5mm. Excessive angular or parallel errors cause display jitter and require adjustment.

5. For long-used electronic scales, aging seals may allow contaminants and oil/water mixtures to affect brush contact resistance, causing display jitter which may indicate early device failure.

6. If the magnetic scale data jitters or does not display at a specific point, inspect cable insulation for damage and possible intermittent grounding shorts to the machine body.

Features of Atonm (Guangzhou) Intelligent Technology Co., Ltd. MRR series magnetic scale read heads:

High reliability: imported flexible wear‑resistant shielded cable, anti-interference hardware and software, and all-metal housing.

High precision: selectable resolutions 1μm, 5μm, 10μm, or custom; parallel installation minimizes mechanical conversion error.

High environmental adaptability: tolerant of oil, liquids, dust and vibration.

Easy installation: compact product design for tight spaces, differential or single‑ended pulse outputs.

Magnetic scales are used in precision cutting saws for aluminum windows, CNC cutting and cornering machines for aluminum doors and windows, heavy automatic planning and milling machines, new high-speed four-axis CNC machining centers, and various machine tool retrofits to improve display accuracy.