Does the Agilent 70952B optical spectrum analyzer fall out of calibration easily? We had two units purchased recently, and their calibration is off by large amounts. We aren't sure if the instrument needs a long warm-up period or if it is just in need of frequent manual calibration.
The procedure we are using is to turn on a source, then push Auto Align on the 70004A, followed by an Auto Measure. One unit is off by 10 db and the other is off by about 4 db. We are using SM FC UPC cable connected to the OSA through the HP Agilent 81000FI FC adapter. As far as we can see, the metallic connector and all fibers and connectors from source to measurement are clean.