Introduction
The MPEX3645X magnetic pickup speed sensors provide an output signal when a ferrous target
passes the tip of the sensor. For uniformly spaced targets such as gear teeth or turbine blades the
output waveform is typically sinusoidal. The frequency of the output signal is proportional to the
rotation speed of the target. The magnetic pickup is a passive device and does not require a power
supply.
Selection
The MPEX3645X magnetic pickup may be used in zones 0, 1, or 2 with flammable gases.
The magnetic pickup (MPU) may be used in the presence of flammable gases and vapours with
apparatus groups IIC or IIB or IIA and with temperature classes T1 or T2 or T3 or T4 or T5 or T6 with
ambient temperature ranges as defined in the certificate and listed on page 4 of this guide.
Installation
The magnetic pickup is to be installed by suitably trained personnel in accordance with the applicable
code of practice (typically EN 60079-14). The pickup must be connected via an ATEX / IECEx (as
appropriate) certified Ex ia barrier with output not exceeding the parameters specified on the
certificate and listed on page 4 of this guide. Typical connection arrangements are shown in figure 1.
MPEX3645X is terminated with an MS10SL-4P connector. We recommend that the mating 10SL-4S
connector is fitted with 2-core screened cable to connect to the control/monitoring instrumentation. It
is advisable to route the cable away from possible sources of interference such as power cables and
relays.
The output of the magnetic pickup is clamped to a nominal 4V peak.
Under certain extreme circumstances, the non-metallic parts incorporated in the enclosure of this
equipment may generate an ignition-capable level of electrostatic charge. Therefore, particularly in
the event of an installation in zone 0, the equipment shall not be installed in a location where the
external conditions are conducive to the build-up of electrostatic charge on such surfaces.
Additionally the equipment shall only be cleaned with a damp cloth.
MPEX3645X User Guide v1.1
01/06/2018
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MPEX3645X
User Guide
Plug and Socket Type
Speed Sensor
Intrinsically Safe
