Omega CYD200 Series, User Manual

Omega Model CYD201/202 User’s Manual 

Installation 2-9 

Connecting Leads To The Sensor (Continued) 

Thermally anchor lead wires at several temperatures between room 

temperature and cryogenic temperatures to guarantee no heat conduction 

through the leads to the sensor. 

2.4.3 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 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. 

CY7-SD

Diode  Sensor  Leads

Anode

Cathode

On the CY7-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 

sensor is the Omega CO Adapter.