+150 °C To -55 °C Extended Temperature Spectroscopy
From a high of +150 °C to a low of -55 °C, Quantum Northwest offers a wide range of temperature control for your spectroscopy experiments.
Extended temperature spectroscopy ranges are available for UV-Vis-NIR, fluorescence, fiber optic, flash photolysis, photoacoustic and circular dichroism applications:
• Versa 20 family of products for UV-Vis-NIR spectrophotometry
• Luma 40 and TLC 50 Legacy families of products for fluorescence spectroscopy
• qpod cuvette holder for fiber optic spectrometers
• Flash 300 stand-alone device for laser flash photolysis and pulsed-laser photoacoustics
• CD 250 cuvette holder for circular dichroism spectrometers
These cuvette holders can be specially built to extend their temperature ranges from their normal range of -40 to +105 °C. Choosing the extended temperature option – denoted by /E – extends this control range to -55 °C to +150 °C. This requires the use of materials that are stable at the high and low temperatures, sensors with extended range, and design details that protect the delicate magnetic stirring motors.
Advice for Operating at High and Low Temperatures
Each of the extended temperature cuvette holders can be used, at least for limited times, at the high end of this range (up to +150 °C).
The lowest temperatures actually achievable depend on how the cuvette holder is used and its environment. These are not cryogenic devices.
The primary limitation is condensation in the form of frost on cuvette surfaces that are exposed to the atmosphere. Frost can be limited using the circulation of dry gas. For cuvette holders used inside the sample chamber of a spectrometer, the whole sample compartment can be purged. This is true for the qpod, which has its own sample compartment surrounding the cuvette holder. The Versa 20, Luma 40 and FLASH 300 can be provided with windowed jackets to trap dry gas around the cuvette, thus greatly extending their range downward.
Achieving low temperatures can be aided by the circulation of precooled liquid through the Peltier heat exchanger. For example, when using ice water at 0.0 °C, all of the cuvette holders will approach -30 °C or so. To go lower, circulation of precooled fluids below 0.0 °C is required. We recommend the use of 30% methanol-water as the circulating liquid, since it has ample heat capacity and low viscosity, permitting adequate flow through the heat exchanger. It should be possible to achieve a sample holder temperature about 25 °C lower than that of the circulating fluid. The lowest temperature that we have reached to date was -52.7 °C with an extended temperature FLASH 300, considerable added insulation, and circulating fluid of -20 °C.
For more, see the Quantum Northwest White Paper on “The highs and lows of working with your benchtop spectrometer at extended sample cuvette temperatures.”