The Scientific Instruments Model Si-415 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-415 Standard Configuration

Model Si-415 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. Consult factory 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

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. For advanced user who wishes to calibrate their own devices/sensors specific to their own environments.

Certain sensor types exhibit interchange resistance or voltage output characteristics to a standard curve. Grouping sensors offered by Scientific Instruments include:
1. Si-415 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-415 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-415 Group A
    +/-0.3K from 1.5K to 25K
    +/-0.5K from 25K to 450K
  • SI-415 Group AA
    +/-0.1K from 1.5K to 25K
    +/-0.5K from 25K to 450K
  • SI-415 Group D
    +/-0.5K from 1.5K to 450K