GM020 MAGNETIC PICKUPS

INTRODUCTION

The GM-020 MAGNETIC PICKUPS convert mechanical motion to an AC voltage without physical interaction or external power. The GM-020 is basically a self-contained transducer which produces a magnetic field that when altered by any moving ferrous object, causes the generation of an AC signal. This AC signal has a frequency directly proportional to RPM when the GM-020 is mounted in proximity to the teeth of a gear on a rotating shaft. Although the use of a gear is simpler, it is possible to attain the actual RPM value of a shaft by using the GM-020 on evenly space screws, holes or flats on the shaft itself.

Applications include tachometry, flowmeters, counting, position measurement, timing, vibration measurement, synchronisation and motion study.

Datasheet GM020.pdf

SPECIFICATIONS

INSTALLATION HINTS AND GUIDELINES

# Drill and tap access to gear in such a way that allows the perpendicular and centralised mounting of the pickup to the teeth of the gear (if no access boss is already present).

# Clean the gear, casing and GM-011 of any metal filings produced by the drilling process.

# Screw sensor clockwise into the tapped hole until it touches the tip of a gear tooth.

# Wind out the pickup 1/4 to 1/2 a turn to give 0.25-0.75 mm gap, check clearance over a full rotation of the ring-gear.

# Use an AC meter to check for the required minimum signal voltage at lowest engine operating rpm. Reduce clearance gap if signal is too low or increase gap if too high.

# NEVER run pickup sensor wires next to high voltage sources or other wires carrying inductive loads or AC current, particularly if cable is not shielded.

# Two core shielded cable with the shield grounded to the engine is recommended.