Do I need to re-calibrate after cleaning my pH-electrode?

Yes and No. 

Yes - after cleaning you need to verify that the analyzer is reading correctly. The easiest way is to see how it reads when placed in 2 pH buffer soltuions. This is what you do when calibrating. 

No - If the readings are within the specifications (+/- 0.01pH, +/- 1 mV for ORP) in the pH buffers a full calibration is not needed. 

Another way to verify that the readings are correct is to take a process sample and accurately determing the pH or ORP value using another method. This may be a Handheld or Portable analyzer, or you may take a sample to the lab. Be aware that there are many processes that will read differently after the sample sits in a sample bottle for a period of time. For those samples the lab reading will be different from the On-line analyzer.