AMETEK 950 MD Mill Duty Housing LDT User Manual

ALL STAINLESS STEEL HOUSING PROTECTS LINEAR
DISPLACEMENT TRA NS DUCE RS FROM HEAT AND
ENVIRONMENTAL DANGERS

OPTIONS:
STROKES FROM 1” TO 240”
AIR COOLING PORTS
VORTEX AIR COOLING
WATER COOLED HEADS
2 CONNECTION POINTS

OFFERS LATERAL AND HORIZONTAL MOVEMENT
TO COMPENSATE FOR MACHINE SLOP

Protection & Mounting Simplicity for
Linear Displacement Transducers

1080 N. Crooks Road • Clawson, MI 48017 • 800-635-0289 • 248-435-0700 • Fax [phone] • www.ametekapt.com

950MD

Mill-Duty Housing

1

Series 950MD Housing

The series 950 Mill-Duty Housing (950MD) wa s designed for
applications where mounting a stand-alone rod style linear
displacement transducer (LDT) is prohibitive.
Potential physical damage, environmental conditions
or mounting limitations are all elements that are
involved in specifying a linear position feedback
system that will perform flawlessly for many years to
come. The 950MD housing has been designed to
eliminate all of the above problems by protecting the
LDT from physical and environmental damage such
as temperature, corrosives, shock & vibration, or
dust and debris. Additionally, the 950MD offers a
simple two point mounting scheme that can
compensate for lateral and/or horizontal movement
of the machine while in operation. Mounting bolts
are provided for both the trunnion mount and rod
ends in either standard steel or optional Stain l es s
Steel when specified.

The 950MD housing is also perfect for retrofitting existing
cylinders with an LDT providing a continuous position
feedback signal. The 950MD allows for a convenient way
to mount the 950MD and internal LDT parallel to the
cylinder. This eliminates the need to tear down and gun
drill the cylinder to accommodate an LDT simply for
providing position feedback that had not previously been
available.

The housing may also be of benefit in this same
configuration when you have an existing cylinder in
operation that does not allow for an easy removal of the
LDT. Old machines and even some existing machines or
newly designed machines did not take into consideration
the need for continuous position feedback. Certain
machines may require that the entire cylinder be
removed in order to replace the LDT.

The actuator contains a 1/2" spherical rod end with
approximately 1" of adjustment (length). This spherical
rod end allows mechanical movement in a horizontal
and/or vertical motion to compensate for any mechanical
slop or misalignment between the housing and machine.
A rear trunnion mount is provided for mounting either
directly in front of the head assembly or on the rear of the
head. An optional 3/4" spherical rod en d can be supplied
on the rear of the unit (see drawing for details).

The back cap is supplied with threaded and plugged
holes that allow for field installation of the 3/4" diameter
trunnion mount bracket to the back cap. The trunnion
mount bracket is positioned at the point where the head
and barrel connect. A simple exchange of hardware is
all that is necessary to move the trunnion mount bracket
to the back cap and plug the no longer required bracket
mounting holes. When ordering the 3/4" rear rod end

option, the trunnion mount bracket is not supplied since it
would not be required.

The actuator rod is supported by two bearings within the
guide tube. The front piston bearing contains a wiper
assembly to keep contaminants from entering the guide
tube. The rear, or movable, bearing assembly is
manufactured from Rulon
polymer material provides low wear and smooth
operation.

The transducer magnet is mounted within the rear
bearing assembly. The magnet is a 1" O.D. cylinder
magnet (SD0410300). The magnet is positioned 2" from
the end of the transducer hex when the actuator is fully
retracted and 5" from the end of the transducer guide
tube when the actuator is fully extended.

The 950MD is designed to incorporate an LDT which has
a minimum 2" Null Zone and 5" Dead Band. The 951
LDT has a minimum 1.5" Null Zone and 2.25" Dead Band
standard. When specifying a 951 LDT to be used in a
Mill-Duty Housing, you must specify a 2" Null Zone and
5" Dead Band minimum to ensure mechanical and
electrical compatibility.

®

. This high-temperature

1080 N. Crooks Road • Clawson, MI 48017 • 800-635-0289 • 248-435-0700 • Fax [phone] • www.ametekapt.com

950MD

Mill-Duty Housing

2

Due to the fact that the standard Mill-Duty Housing has a
mechanical stroke identical to the LDT active stroke, no
physical over-stroke exists. If it is possible that the
machine being coupled to can extend/retract beyond the
stroke supplied, damage to the Mill-Duty Housing and
possibly to the machine might occur. To compensate for
this we call out fully retracted/fully extended over-stroke
dimensions for the Mill-Duty Housing. These values are
essentially the additional stroke length added to the Mill­Duty Housing. The reason they are called out separately
is to alert the user that when entering these areas, they
are out of the LDT active stroke area. If an extended
over-stroke is specified, the LDT must be ordered with
a Dead Band of 5" + X (extended stroke value). If a
retracted over-stroke is specified, the LDT must be
specified with a Null value of 2" + Y (retract over-stroke
value).

The Mill-Duty Housing offers either a conduit entrance for
hard wiring directly to the LDT within the head or an
external connector and mate. The connector attaches to
the LDT inside of the housing via a small pigtail
connector within the head.

Detailed Product Description and
Materials of Constructio n

The 950MD consists of a 304 Stainless Steel body,
barrel, piston, head and trunnion mount bracket.

The standard 1/2" diameter rod en d with m ounting bolt,
the 3/4" diameter trunnion mounting bolt, and some of
the optional MS connectors on the head are the only
items that are not Stainless Steel on the standard
assembly. This is also true of the optional 3/4" diameter
front and rear rod ends with their mounting bolts. These
rod ends and all mounting bolts can be ordered in
Stainless Steel as an option. The 12mm Euro connector
options C3 and C4 come standar d in Stainless Steel.
Consult the factory for further details.

The 950MD head assembly is removable to allow
installation of a rod style LDT that will screw into the
standard 3/4" - 16 x 1.00 mounting thread. An optional
Metric thread of M18 X 1.5 can also be supplied upon
request. The head contains a 1/2" NPT conduit port for
wiring to the LDT or optionally an MS connector can be
installed for the external wiring. Use of the MS connector
will require that the LDT also have a connector on it in
lieu of a potted cable.

This will allow for a quick connect at the LDT head
internally and on the 950MD head externally. The
950MD head is sealed with O-rings and also contains
two threaded air purge openings that are plugged but
available for use to air cool the LDT head with filtered
and regulated air. By removing the plugs and installing
the proper size air fittings, you can cool the head
electronics for high temperature applications. An
optional Vortex air cooler m a y also be specified for the
head and/or barrel or an option al water jacket for the
LDT can be supplied. See the 950MD dimension
drawings for further details.

Consult Factory if installing
950IS into 950MD H ousing

1080 N. Crooks Road • Clawson, MI 48017 • 800-635-0289 • 248-435-0700 • Fax [phone] • www.ametekapt.com