Model SI-410 Silicon Diode Temperature Sensors

The Scientific Instruments Model Si-410 Silicon Temperature Sensors operate over a wide temperature range and are miniature in size. They are linear over a wide temperature range interval, and have high sensitivity in their lower range. The silicon diode temperature sensors are interchangeable to a standard V/T curve.

Model Si-410 Standard Configuration

Model Si-410 and Si-420 sensors are normally mounted in a gold-plated copper case with four 36 AWG polyimid coated, color-coded, phosphor bronze leads. Case size is 0.093″ diameter by 0.250″ long. Special leads of phosphorbronze or manganin wire at various lengths can be furnished at a minimum additional cost. Other packages can be supplied, contact us for details.

Sensor Accuracy / Interchanqeability
As you review our various sensor types, you will notice that we offer the advantage of “Grouping” / “Interchangeability.” We presently offer five levels of interchangeability /accuracy.

Fundamentally, cryogenic temperature sensors are supplied in three categories:
• Uncalibrated
• Grouped
• Calibrated

Uncalibrated
As the name implies, an uncalibrated sensor is provided to our customers as representative of a particular sensor type, but with no specific calibration information.

Grouped
Certain sensor types exhibit interchange resistance or voltage output characteristics to a standard curve. Grouping sensors offered by Scientific Instruments include:
1. Si-410 Silicon Diode
2. RO-l05 Ruthenium Oxide
3. RO-600 Ruthenium Oxide

The ability to offer interchangeable sensors comes from a thorough analysis and understanding of the basic material to be used as the sensing element. The primary advantage to “grouping” sensors is that they all adhere to a standard V/T or R/T curve, thus eliminating the need and expense of an individual calibration. Each Si-410 sensor is tested in liquid helium, liquid nitrogen and ice. Each sensor must repeat in liquid helium ± 0.01 K over a ten cycle test. The sensors are then grouped according to the following table:

Silicon Diode Temperature Sensor Accuracy & Interchangeability
Si-410 Group B
± 1.0 K from 2.0 to 25 K
± 2.0 K from 25 to 450 K
Si-410 Group C
± 0.5 K from 2.0 to 25 K
± 1.0 K from 25 to 450 K
Si-420
± 2.0 K from 4.0 to 25 K
± 5.0 K from 25 to 450 K

Physical Configuration/Diameter/Length	Model 25 Bobbin/0.562 inches/0.200 inches (Unencapsulated size = 0.965 mm H x 1.27 mm W x 2.79 mm L)
Calibrated	All sensors offered by Scientific Instruments may be offered as individually calibrated units, with the exception of our thermocouples. The sensors are placed into a calibration cryostat, and data is recorded for each sensor using an NIST traceable standard against the ITS-gO standard.
Custom Calibration	Individual Model Si-410 sensors can be calibrated at 10 or 100 microamps over various standard temperature ranges at the following accuracies: ± 0.05 K from 1.5 K to 25 K ± 0.10 K from 25 K to 450 K.

Physical Configuration/Diameter/Length

Model 25 Bobbin/0.562 inches/0.200 inches (Unencapsulated size = 0.965 mm H x 1.27 mm W x 2.79 mm L)

Calibrated

All sensors offered by Scientific Instruments may be offered as individually calibrated units, with the exception of our thermocouples. The sensors are placed into a calibration cryostat, and data is recorded for each sensor using an NIST traceable standard against the ITS-gO standard.

Custom Calibration

Individual Model Si-410 sensors can be calibrated at 10 or 100 microamps over various standard temperature ranges at the following accuracies: ± 0.05 K from 1.5 K to 25 K ± 0.10 K from 25 K to 450 K.