For many vibration analysts, a magnet is the point of contact between them, with all of their sophisticated technology, and the rotating equipment they wish to monitor. This being the case, the magnet and its mounting characteristics occupy a very important position in the scheme of what they do every day, yet this crucial part of their occupation is most often taken for granted.
Check your magnets frequently! Make sure the sensor is securely bonded to the magnet so the least possible interface loss is experienced. If you have to help hold the magnet and sensor onto the equipment, it’s time to get a new magnet. The magnet should be strong enough to support the weight of your cable assembly without rocking at all when the cable is swinging. When your sensor and magnet are not in use, make sure the magnet has something to pull against like a washer or what many analysts have found to be very useful for magnet storage… the side of a metal file cabinet.
Maintenance Tips, Vibration Analysis by Mike Fitch CRL