Lake Shore Model 102 User’s Manual
Installation 2-3
Thermally anchor lead wires at several temperatures between room
temperature and cryogenic temperatures to guarantee no heat conduction
through the leads to the sensor.
2.4.2 Sensor Mounting
Before installing a diode sensor, identify
which lead is the anode and which is
the cathode. When viewed with the
base down and the leads towards the
observer, the anode is on the right and
the cathode is on the left. The Lake
Shore DT-470-SD silicon diode sensor
lead configuration is shown to the right.
For other sensors, read accompanying
literature or consult the manufacturer to positively identify sensor leads.
Lead identification should remain clear even after sensor installation. Record
the sensor serial number and location.
On the DT-470-SD, 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
DT-470-SD sensor is the Lake Shore CO Adapter.
CAUTION: Lake Shore 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 DT-470-SD 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.
DT-470-SD
Diode Sensor Leads
nodeCathode
To Next Page
Loading...
