MKS HPS 917, Operation And Maintenance Manual

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10 Pirani Vacuum Sensor System
To fit the KF 16 port to a KF 10 port, use an HPS TM adaptive centering ring
(see Accessories, p. 21).
To fit the Sensor with the 1 /
8
" NPT, do not use the case for tightening. The
Sensor’s vacuum tubing has
9
/
16
" hex flats for tightening. Wrap some Teflon
®
tape on the threads of the Sensor, in the direction of installation, to ensure a
leak-free seal.
Instead of the NPT fitting, you may opt to use the ½" O-ring compression
seal against the vacuum tubing above the thread,
but the O-ring seal cannot
be used for positive pressure applications.
A solid electrical connection between the Sensor and the
grounded vacuum system must be provided to shield the
tube element from external radiation sources. In applications
where the system may be exposed to large voltage
fluctuations, a centering ring with a screen should be
installed, and the screen
and tubing then grounded.
Pirani Controller Installation
Controller Mounting
The Series 917 Pirani Controller is designed for either panel mounting or for
stand-alone use. Regardless of the method you choose, assure adequate
ventilation to the Controller with at least a ½ inch left open above and below it.
Adhesive backed rubber feet are provided for bench top use. Remove the
adhesive backing from each foot and apply them to each corner of the
aluminum bottom surface.
An optional hardware kit is also available for mounting the Controller into a
standard ¼ DIN cutout in a panel up to
3
/16-inch thick (see Accessories,
p. 21). A dimensioned illustration shows the required cutout on the top of the
next page. Leave at least 3 inches of clearance behind the Controller's rear
panel to accommodate the connectors and cables.
Mount the Controller into the panel by slipping it through the cutout from the
front. Slide the panel mounting brackets into the slots on either side of the
Controller from the rear, and secure them with the thumbscrews provided.
Electrical Connection of the Pirani Sensor to the Controller
Connect the Pirani Sensor to the Controller with a sensor cable (see
Accessories, p. 21). This cable has a standard octal socket. With an
integrated polarizing tab, the socket has sufficient contact pressure so that
strain relief is unnecessary in most applications.