Balluff’s BML linear position encoder family provides direct measurement of a load’s linear position and is well suited for high speed and high accuracy applications (up to 48 m of travel at 20 m/s, with position resolution down to 1µm). It also eliminates mechanical wear and signal degradation in a dirty environment (e.g. oil, dust).

BML Main Features:

• Accurate and affordable direct load linear position monitoring
• Precise positioning regardless of actuator technology or mechanical wear
• Multiple levels of precision tracking, tailored to your accuracy requirements
• Non-contact reliability and performance
• High speed tracking – up to 48 meters at 20 m/s

Benefits of Direct Measurement of Load
In contrast to indirect rotary encoder-based positioning systems, direct load measurement is more accurate, reliable, and eliminates incorrect position information due to backlash in the linear drive system. Whether ball screw, synchronous belt, or rack and pinion, BML accurately monitors linear load position independent of the specific actuator drive technology employed. This allows machine OEMs to choose inexpensive drive solutions without sacrificing position tracking accuracy. It’s no longer necessary to use more costly “pre-load” or “zero backlash” actuators just to improve the accuracy of the rotary encoder at the motor shaft. Additionally, the BML magnetic linear encoder is immune to catastrophic position errors caused by drive belt slippage or breakage that can affect motor shaft mounted rotary encoders.

Lower Cost Solution
Compared to many linear encoder alternatives, Balluff’s BML tolerates a wider operating gap between the sensor head and encoded magnetic tape without sacrificing accuracy. The S1A gap is up to 0.35 mm and the S1B, S1C, and S1E gap is up to 2.0 mm. With typical linear encoders, sensor gap specifications that are very small can drive system costs up, since machine tolerances must be tight enough to meet the stringent gap requirements of the encoder. This wider gap can help lower machine costs by allowing manufacturing tolerances to be relaxed and by enabling the use of less expensive, lower precision linear slide components.

Multiple Levels of Precision
The BML system is available in multiple versions tailored to users’ accuracy requirements.

Series	BML-S1A	BML-S1B/BML-S1E	BML-S1C
Output Signal	digital analog (sin/cos)	digital	digital
Resolution	1...10 µm	5...50 µm	100...2000 µm
System Accuracy	±10 µm/ ±20 µm	±50 µm/ ±60 µm/ ±100 µm	±100 µm
Distance to Tape	0.1...0.35 mm	0.1...2 mm	0.1...2 mm