Instructions, Silicon Diode Temperature Sensor
Installation, Model DT-470, 471, 670, and 671 CY Package
Lake Shore Cryotronics, 575 McCorkle Blvd. Westerville, OH 43082
Phone (614) 891-2243
CAUTION:
This temperature sensor is sensitive to electrostatic discharge (ESD). Use ESD
precautionary procedures when handling, or making mechanical or electrical connections to this
device in order to avoid performance degradation or loss of functionality.
There are three aspects of using a cryogenic temperature sensor which are critical to its optimum performance. The first
involves the proper mounting of the sensor package; the second relates the proper joining of sensor lead wires and
connecting wires. The final concern is the thermal anchoring of the lead wires. Although the sequence in which these areas
should be addressed is not set in stone, all elements covered under
each aspect should be adhered to for maximum operating capabilities
of the sensor.
SENSOR MOUNTING
The DT-470/471/670/671 CY package combines a standard SD sensor
with a gold-plated copper mounting bobbin to form the CY package.
The mounting bobbin of these packages contains a 3.1 mm (0.122 in)
diameter centered hole designed for mounting with a #4-40 or M3
screw.
1. A threaded hole in your mounting surface is necessary for
mounting the sensor package. The hole in the sensor package will
accommodate a #4-40 or M3 screw. A brass screw is recommended due to the thermal contractions/expansions of the
final assembly.
2. The threaded hole and surrounding surface should be cleaned with a solvent such as acetone followed by an isopropyl
alcohol rinse. Allow time for the solvents to evaporate before sensor mounting.
3. Apply a small amount of Apiezon
®
N grease to the threads of the screw. To ensure good thermal contact between the
sensor and mounting surface use an indium washer/preform or a thin layer of Apiezon
®
N grease between the mounting
surface and the sensor package.
NOTE:
An overabundance of grease will increase the thermal barrier. Keep the thickness to 0.05 mm or less.
4. Insert screw through sensor mounting bobbin and tighten screw firmly enough to hold sensor in place. Avoid over
tightening (torque of 3 to 5 in-oz [0.02 to 0.035 N-M] should be sufficient).
NOTE:
This package is designed for use up to 400 K (127 °C); subjecting sensor to
temperatures in excess of this will cause a shift in the sensor values.
LEAD ATTACHMENT
The SD sensor has been attached to the mounting bobbin and encapsulated in Stycast
®
epoxy.
The 914 mm (36 in) sensor leads are 30 AWG, Teflon
®
coated wire which are thermally
anchored to the bobbin. Standard lead configuration for the CY is a 2-lead device
[Green = Cathode (
–), Yellow = Anode (+)].
914 mm (36 in) lead wire is attached during the production process. If additional connection wire is required, use the following
instructions.
1. Prepare the sensor leads with a RMA (rosin mildly active) soldering flux. Use a low wattage soldering iron and tin leads
with a minimal amount of 60% Pb 40% Sn solder. Clean off residual flux with a rosin residue remover.
2. Strip the insulation from the connecting wires by delicately scraping with a razor blade, fine sand paper, or steel wool.
Follow the same procedure in step 1 for preparing connecting wires.
NOTE:
This package is designed for use up to 400 K (127 °C), subjecting sensor to temperature in excess of this will
cause a shift in the sensor values.
