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Platinum

Platinum features

Temperature range: 14 K to 873 K (model dependent)
Available as a traditional wire-wound package or a bolt-down adapter
Conforms to IEC 751 standards for platinum sensors
High reproducibility: ±5 mK at 77 K
Low magnetic field dependence above 40 K
Excellent for use in ionizing radiation
Calibrated options for sensor groups with a single curve

Platinum sensor applications

PT-100 platinum resistance thermometers (PRTs) serve an important role in both cryogenic research and industrial cryogenics applications.

Research

Many cryogenic research platforms also include high-temperature capabilities, extending hundreds of degrees above room temperature. These platforms need temperature sensors that can both measure and survive these extreme temperatures. With a useful temperature range of 14 to 873 K, platinum sensors are invaluable for this application.

Note: Platinum sensors lose sensitivity below 14 K. For temperatures below this, please see the sensor selection guide, as there are sensor options for lower temperatures, though there are none that can also exceed a 500 K maximum temperature.

Production and transport of liquid cryogens

The production and transport of many liquid cryogens (liquid nitrogen in particular) often see platinum sensors as the sensor of choice for temperature monitoring. Their bolt-down package option and interchangeability options allow multiple sensors to be used with a single temperature curve, making them simpler to implement and maintain.

Typical platinum resistance

Typical platinum sensitivity

Typical platinum dimensionless sensitivity

PT-103, PT-103-AM, PT-111, temperature probes

Temperature curve options

In addition to the natural temperature accuracies of the 100 Ω Class B platinum sensors, Lake Shore offers several calibration and characterization options to suit different applications.

Uniquely characterized options

Temperature vs. resistance curve is uniquely tailored for each sensor
Not possible to use the same curve accurately with other sensors
Achieved by measuring each sensor against known temperature standards at numerous temperature points
Generally results in the most accurate measurement solution

Interchangeable options

Sensors that are able to use a single temperature vs resistance curve that is not unique to any one sensor
Each sensor is unique but will fall within a specified offset from the reference curve
Generally less accurate than individually characterized sensors, but simpler to implement and maintain

Calibrated

Sample accuracies
Temperature	Accuracy
30 K	±10 mK
77 K	±12 mK
300 K	±23 mK

Characterized in a Lake Shore metrology cryostat from 14 K to one of several maximum temperatures. The most accurate solution available, but requires more time and effort, attracting a higher price than other options.

Will be the required sensor choice when the most reliable temperature measurements are of critical importance.

SoftCal™

Sample accuracies
Temperature	Accuracy
30 K	Not specified
77 K	±250 mK
300 K	±250 mK

Each sensor is measured at several temperature points to create a unique curve adapted from the typical 100 Ω platinum sensor.

Useful in situations where a smaller number of sensors are required with only moderate accuracy is needed, and the sensors will primarily measure at or above LN₂ temperatures

Matched

Sample accuracies
Temperature	Accuracy
30 K	Not specified
77 K	±125 mK
300 K	±500 mK

A group of sensors (now up to 50) that are measured and selected to ensure they all fall within 0.1 K of a single reference sensor in that group at 77.35 K (LN₂). This results in a group of sensors with a single curve that is significantly more accurate than standard Class B platinum sensors.

This approach makes them ideal for applications such as liquid nitrogen transport lines in large cryogenic facilities, where the temperature sensors spend the majority of their time measuring the presence of liquid nitrogen.

More about matched sensors...

Uncalibrated

Sample accuracies
Temperature	Accuracy
30 K	Not specified
77 K	±1200 mK
300 K	±500 mK

The default accuracy for 100 Ω Class B platinum sensors.

Most useful for temperatures that are relatively close to room temperature as these sensors become much less accurate at cryogenic temperatures or for situations where absolute accuracy is less important than identifying a change in temperature.