Fig.1 Triaxial Accelerometers are in increasingly common usage with the advent of triaxial based data collectors. The triaxial accelerometer is three single axis accelerometer capsules in a single housing with signals connected by a single connector or single integral cable.
Fig.2 It is important that an established XYZ coordinate on a rotating asset is measured consistently by any temporarily installed triaxial accelerometer. These measurements might be taken over a number of years, using a number of different sensors and by a number of different technicians.
Fig.3 The use of a triaxial accelerometer with a through bolt means that the accelerometer XYZ axis can easily, and always be aligned to that of the asset that is being measured. However side exit connections and the bolting down of a sensor are not always ideal for the rapid measurement of 100’s of machines during a typical ’route’.
Fig.4 For rapid measurements a quick means of attaching a triaxial accelerometer must be found and where cable management issues are minimized. This is achieved by using a top entry accelerometer, a magnet or a quick fit connection.
Fig.5 The problem arises with both mounting techniques in that the orientation of the triaxial accelerometer cannot be guaranteed. One sensor will be orientated in one direction and then a different magnet or Quickfit connection will be oriented in another. To make sure of consistent orientation, threads must start in the same orientation and always be connected to the triaxial accelerometer in exactly the same way.
Fig.6 This is achieved by having a precision machined and threaded adapter that is always mounted to the accelerometer in the same orientation. This is facilitated by the use of an orientation dowel fitted to the base of the top entry accelerometer.
Fig.7 The mating base is adhesively mounted to the machine being monitored in the orientation marked on it. The mating receptacle is oriented to the accelerometer using the orientation dowel and then secured using the mounting screw.
Fig.8 The mounting system consisting of:
1.) HS173R triaxial accelerometer
2.) HS-AS221-1/4 mounting receptacle and attaching thread
3.) HS-AS222 Quick fit Adhesive Pad