Please take the time to read this briefing about the importance of having clean and proper cooling water for your SEM, TEM, or Dual Beam.  We will be releasing Service Bulletins at least quarterly as a service to our customers.

Chiller/Cooling Water Maintenance

As part of TSS Microscopy’s microscope services and in an effort to keep your scope up and running in tip-top shape, TSS is releasing quarterly letters to our customers to advise of some basic maintenance items that should be checked!

This month – please focus on the chilled water that cools your scope.  Many of the SEM, TEM and Dual Beam that TSS services have chillers that are used to cool lenses or pumps.  It is critical that the water in the chillers is of the proper chemistry, temperature, and cleanliness.

Here are some of the basics that we would ask you to check.  It is recommended to check the chiller water twice per month!  Please do indeed contact us if there are questions or if you need help.

1.     pH.  The pH of the water has to be correct!  If the water is too acidic it can erode parts and severely decrease the lifetime of you scope. The pH can be checked with standard pH paper and should be between 7.5 to 9.  If it is lower, it is acidic, and some action needs to be taken (contact us for more information please if this is the case).  See the photo below for what overly acidic water can do to a lens in the SEM.  It can be catastrophic.

2.     Temperature.  The temperature of the water that cools your scope is very important.  If a chiller is set too hot, insufficient cooling can occur, and drift and other bad effects will be noticed.  If it is too cold, condensation can occur and this can also have detrimental effects.  The temperature is typically between a range of 17-21°C (this depends a bit on the environment and the scope, so please contact us if questions).

3.     Cleanliness.  Dirty water, algae contaminated water, and clogs are some of the most difficult and service intensive issues we see. This can cost a lot of time and money for everyone involved.  It is very important to have the water clean and algae free.  Without clean water, lenses can become clogged and other key components of your scope can heat up!  An inline filter (5um) and opaque water tubing can help to reduce the chances of algae growth.  If these are not on your system, please let us know and we can work with you to make sure your system is best setup for clean water and long microscope life.

Each chiller manufacturer has specific recommendations to maintain clean cooling water.  Here are some of the key points — TSS can provide more details as needed.

Haskris chillers:

–       Distilled water is preferred.  This is because this water has been boiled and is free from organisms

–       Add lab grade propylene glycol to create a 10% solution

–       Add dichlorophene, which is a fungicide, and is sprinkled on the top surface of the chiller.  Use a small amount to cover the top surface of the water in the chiller tank

ThermoCube chillers:

–       Use the colorless or blue versions of Koolance

–       http://koolance.com/liq-702-liquid-coolant-bottle-high-performance-700ml-blue

–       Water or ethylene glycol mixtures can also be acceptable

In summary, TSS recommends that the following items are checked now:

1.     Validate that the pH of your cooling water is correct using a pH paper test.

2.     Validate that the temperature of your chiller is set correctly.

3.     Check the cleanliness of the water by looking in the chiller and noting if you see any algae or floaters.  Also check the cooling lines/tubing.  If you do see something that concerns you, take a photo and contact TSS.  We will make recommendations on what you should do.

4.     Check the flow rate of the chiller.  Make sure the water is flowing and at the correct specified values for your instrument.  Contact TSS for more detailed information on your specific scope.