Posted by Dan (22.214.171.124) on March 20, 2010 at 22:12:41:
In Reply to: stable surroundings posted by Pavel Zarecky on March 20, 2010 at 07:14:04:
: Hello. Iīd like to ask about recommended values of temperature and humidity for SRA (SRP) measurement? What about light intensity? And other accessory effects? thanks a lot for your answer. best regards Pavel
SRA can be performed in a standard room without a 'class.'
Humidity has not been a problem however temperature can be if you expect a range of more than 1-2 degrees centigrade. We've found that the HVAC settings that are set to a comfortable level for people (70-75F) will work for SRA. The important thing to remember is that whatever temperature you calibrate the machine at is the temperature you want to run test samples at.
Light, noise and vibration can all be bad for SRA. If you have a probe near heavy machinery, the vibrations can both create noise in the data collection and increase the wear on the probe tips which will lead to the machine going out of calibration sooner. Since noise is also a vibration source, the same problems apply. Light doesn't always create a problem but with some samples it can create a photovoltaic reaction that will add (or subtract) from the voltage applied by the probe thereby fooling the instrument into a different reading. Since we don't know which samples will be affected, we have light shielding on every machine and the machines are in smaller rooms that can be individually darkened if extremely light sensitive samples are tested.
Lastly, keep the air clean. I canít tell you how many machines Iíve seen that have been exposed to HCL or other chemical leaks. And when it isnít chemicals, itís dust! The footprints our probes leave behind are hard enough to see with clean optics.