Instructions,
Platinum Resistance Thermometer Installation
Lake Shore Cryotronics, 575 McCorkle Blvd. Westerville, OH 43082
Phone (614) 891-2243 – Fax (614) 891-1362 –
Model PT-102, PT-103, and PT-111
The PT-102, PT-103, and PT-111 are wire-wound thermometers and normally used as
secondary standards. However, these thermometers should be treated in the same manner
as any precision instrument. It is recommended that they not be subjected to any
unnecessary shock or rough mechanical treatment.
In reading the thermometer, it is important to use the proper measuring current. An excessively
high current will cause joule heating (I
2
R), thus giving erroneous reading. Lake Shore
recommends a maximum power dissipation (joule heating) of 10 µW: the same as used in
calibration. The recommended measuring currents to avoid joule heating are as follows:
0
Ω
to 200
Ω
0.5 mA
200
Ω
to 1200
Ω
0.1 mA
There are three aspects of using a cryogenic temperature sensor which are critical to its optimum performance: 1) proper
mounting of the sensor package, 2) proper joining of sensor lead wires and connecting wires, and 3) proper thermal anchoring
of the connecting wires. Although the sequence in which these concerns should be addressed is not fixed, all elements
covered under each aspect should be adhered to for maximum operating capabilities of the sensor.
MOUNTING ADAPTERS
PT-102-AL and PT-103-AM each include a platinum RTD sensor mounted into a flat aluminum block. They can be mounted to
any flat surface with a 6-32 or M3 screw (not included) and Inconel® Belleville washer (included).
Adapter material:
6061 Al block (PT mounted to adapter using Cotronics Durabond® 950 Al-based adhesive)
AL leads:
Two 0.010-inch diameter: 10.160 ±1.270 mm (0.400 ±0.050 in) long
AM leads:
Two 0.010-inch diameter: 15.240 ±1.270 mm (0.600 ±0.050 in) long
Lead material:
Platinum
Mass:
PT-102-AL: 3.8 g, PT-103-AM: 2.1 g
Limitation:
The aluminum alloy limits the upper useful temperature of these configurations to 800 K
PT-102-AL
PT-103-AM
