Recently at a customer visit, the customer informed me that their peltier plate was really struggling to reach 5°C which is the low end of where they test. The most common cause is a blocked cooling passage through the core of the peltier plate. This blockage causes the hot side of the peltier plate to fight the cold side and significantly limit the low end of the temperature range. In this case, the cause was found to be a weakened/dying peltier cell as there was no cooling blockage. The peltier plate was replaced with a Liberty Instruments Re-manufactured one. The performance comparison is shown in the picture below.
If you would like to test this yourself, just run a simple oscillation temperature ramp to 0°C at 8°C/min and make sure to enter a “Soak Time After Ramp” of at least 10 minutes. A healthy peltier plate will achieve this with little effort. If your peltier plate is struggling, please contact us to help troubleshoot! We offer next-day shipping of our re-manned units and a 1-2 day repair/cleaning service if you would prefer to just fix your current peltier plate.
NOTE: The low-end specification of a peltier plate depends on what fluid circulating system you have. In this case, the customer had an air-cooled circulator using Koolance fluid. In this case the specification is -15°C.