December 6, 2010

Erratic Behaviours In Your Windows Based Measurement Instruments



Has your measurement instrument been acting weird lately? Perhaps you are experiencing one or more of the following symptoms:


  • The instrument GUI is sluggish, laggard or slow to respond. 
  • Measurement readings are unstable, exceeding the measurement uncertainty of the instrument.
  • The instrument (in this case a network analyzer) seem to be having unreasonable amount of errors even though you have just completed a calibration.
  • After calibration, the measurement seemed fine at first but started to degrade or become unstable after several rounds of measurement (and you've ruled out the possibility of bad connections and  wrong physical setup etc)
If you do experience the above, you should next ask yourself this question: "Is my measurement instrument running on Windows OS?" 

If the answer is YES, then there is a high possibility that your instrument has been infected with VIRUSES and TROJANS. You would likely to notice that you do not have an anti-virus installed or that the virus definition is grossly outdated.


Recently, I experienced such behaviour in some Agilent PNA Network Analyzers. These Network Analyzers are running on Windows OS. One of them was running the 85070E Materials Measurement Software and had a really weird behaviour, almost as if it was going crazy - one moment the permittivity measurement of the water was fine and another moment it was haywire. 

At first I thought it might be a cable problem so I tested out the response of the cable but it was fine. I inspected the rest of the setup and they were fine too. Then I noticed that the software seemed to be taking an unusually longer time to respond to mouse clicks immediately after the calibration was completed. That was when I thought that the issue might be a software problem. 

One full virus scan later, over 60 viruses and trojans were found to be residing in the Network Analyzer! After eliminating the viruses and trojans, the measurements became stable and there wasn't any sluggish response in the GUI.

This solution could possibly be applied to a spectrum analyzer, network analyzer, oscilloscope or any other instruments loaded with Window OS, if they appear to behave erratically. You might have a whole colony of viruses and trojans partying in your instrument!


It's time to crash the party.