Probe question

[ljdm]

Was looking at my probe, noticed it has a greater range of motion in 2 directions than 2 others. Barely any movement allowed in the 2 directions, while the other 2 move alot farther. Question - is this normal, and could it have anything to do with the probe scratching surfaces, due to it not being able to move enough?

[Jeff_Birt]

The probe only needs to just barley move to open a contact. The scratching comes about because it is basically dragging the metal tip across what you are scanning. Not dragging exactly, it moves the probe down until it hits something, then back up until its clear, then over a step if nothing is there it will move down until it finds something again. Repeat several million times and you have a scanning operation.

I have found that cleaning the contacts of the probe every few months helps a lot. Ted Grinnel originally posted some directions for this sometime back. Might be worth searching for.