Stand-Alone Continuous Monitor Unit for Refiner; 1 VIB Channel, 1 SPM Channel
A special kind of MG4 is the MG4-Ref11, developed for the pulp and paper industry to continuously monitor refiners. This unit has been adapted to the special requirements for extremely fast measurements necessary to detect imminent disc segment failure. The Machine Guard MG4-REF11A is a measuring unit for the continuous monitoring of mechanical shocks arising when the disc segments in a refiner touches each other (one channel) and machine vibration (one channel). It measures vibration severity (true RMS value of vibration velocity) according to ISO 2372.
A shock pulse transducer is installed on the machine housing of the refiner so that mechanical shocks from the disc segments are picked up by the transducer with the smallest possible damping. The transducer is connected to MG4-REF11 that analyses the signals received, taking into account amplitude and frequency of occurrence. If the disc segments run together, a relay is activated, and a signal is given to open the disc gap. The display shows measuring results for both channels. The measuring results can be put on any of the available analog output channels and connected with any of the relays.
For each channel it displays:
- Status display (green - red light) and system fault (yellow light)
- Display of measured value with continuous updates
- Analog output current 4-20 mA with programmable range
- Relay action at two programmable alarm levels (red alarm)