Omega Engineering CYTX231 Series, User Manual, Page: 16 / 38

Omega Model CYTX231 User’s Manual
2-4 Installation
Sensor Mounting (Continued)
On the CY7-SD7, the base is the largest flat surface. It is sapphire with gold
metalization over a nickel buffer layer. The base is electrically isolated from
the sensing element and leads; make all thermal contact to the sensor
through the base. A thin braze joint around the sides of the SD package
electrically connect to the sensing element. Avoid contact to the sides with
any electrically conductive material.
When installing the sensor, make sure there are no electrical shorts or
current leakage paths between the leads or between the leads and ground.
If IMI-7031 varnish or epoxy is used, it may soften varnish-type lead
insulations so that high resistance shunts appear between wires if
sufficient
time for curing is not allowed .
Slide Teflon
®
spaghetti tubing over bare leads when the possibility of
shorting exists. Avoid putting stress on the device leads and allow for
thermal contractions that occur during cooling which could fracture a solder
joint or lead if installed under tension at room temperature.
For temporary mounting in cold temperature applications, apply a thin layer
of Apiezon
®
N Grease between the sensor and sample to enhance thermal
contact under slight pressure. The preferred method for mounting the
CY7SD7sensor is the Omega CO Adapter.
CAUTION: Omega will not warranty replace any device damaged by
user-designed clamps or solder mounting.
For semi-permanent mountings, use Stycast epoxy instead of Apiezon
®
N
Grease. NOTE: Do not apply Stycast epoxy over the CY7-SD7 package —
sensor stress may shift the readings. In all cases, periodically inspect the
sensor mounting to verify good thermal contact to the mounting surface is
maintained.
For the Model CYTX231SD, Series CYTX231P Platinum Sensors follow the
same basic procedures for diode type sensors. However, Platinum sensors
have no lead polarity, and some of the materials used at cold temperatures
will not tolerate the high-temperature range of the Platinum sensor.