Low Vibration Pulse Tube (Model PT-950-FTIR) for FTIR Applications

FTIR (Fourier transform infrared) spectroscopy often requires that the cryostat be inserted into the sample compartment of a spectrometer for low-temperature measurements. Since spectrometer optics are usually sensitive to vibrations, a low-vibration approach is needed; however, low-vibration designs using special isolated stands are not usually practical for interfacing with a spectrometer. An alternative approach is to use a pulse tube refrigerator to provide cooling. These coolers feature very low vibrations—particularly on the room temperature housing—allowing the cryostat to be mounted directly on the spectrometer. Samples are cooled by exchange gas for rapid sample exchange and uniform cooling. As with most standard Janis designs, the PT-950 may be modified to suit any low-vibration application.

Standard configuration

PT-950-FTIR mechanical drawing

As with the SHI-850 design, the PT-950 design may be modified to suit any low-vibration application.

FTIR options for the PT-950 include:

  • Multiple-position sample holders, allowing the user to switch between a reference path and several samples without removing the sample positioner
  • Precision linear and rotary manipulators, manually or remotely controlled
  • Mounting flange to fit many commercially available spectrometers
  • IR windows, including diamond, ZnSe, polyethylene, polypropylene, sapphire, and more
  • Windows available in either plane parallel or wedged configurations
  • High temperature operation up to 500 K or 800 K (with sample in vacuum)

PT-950-FTIR Specifications

Sample environmentSample in exchange gas
Temperature range~7 K to 300 K
Temperature stability (with controller)±50 mK
System weight~110 lb
Note: Specifications do not include parasitic or experimental heat loads.


Janis — a Lake Shore Company
PT-950-5 pulse  tube for FTIR