• Discovery MR750 3.0T System Service Methods
  • 5690009-2EN Revision 4
  • Object ID: 00000018WIA300DBE20GYZ
  • Topic ID: id_13107537 Version: 3.1
  • Date: Nov 27, 2019 10:21:33 AM

Gradient and RF Body Coil Air Flow Sensor Replacement

Prerequisites

Table 1. Personnel requirements
Required personsPreliminary requirementsProcedureFinalization
2Not Applicable120 minutes45 minutes
Table 2. Tools and test equipment
ItemQuantityEffectivityPart numberManufacturer
Non-Magnetic Service Tool Kit1-

5112581

-
Table 3. Replacement parts
ItemQuantityEffectivityPart numberManufacturer
Air Flow Sensor1-

FRU number depends on system type. See Field Replaceable Units (FRUs).

-

About this task

This procedure describes the replacement of the gradient and RF body coil air flow sensor.

Procedure

  1. Perform LOTO on the RF amplifier and PEN cabinet. See the MR Service Safety Manual, PN 5452735.
  2. Remove the side covers and left skirt cover to access the SRI. See Side Cover Removal and Installation and Skirt Cover Removal and Installation.
  3. Remove the split bridge. See Bridge Removal and Replacement.
  4. Remove the front end bell. See Front End Bell Removal and Installation.
  5. Disconnect the RF body coil air flow sensor housing from the scan room interface (SRI).
    Figure 1. Air Flow Sensor Housing with Connector
    Note:

    The illustration below is for reference only; sensor head housings are not shown.

    Figure 2. Air Flow Sensor Assembly Drawing
  6. Locate the RF coil air flow sensor head housings at approximately the 11 o'clock and 1 o'clock positions on the magnet enclosure.
    Figure 3. RF Coil Air Flow Sensor Head Housings
  7. Remove and save the two screws securing each sensor head housing to the magnet enclosure.
    Figure 4. Removal of Air Flow Sensor Head Housings
  8. Remove each sensor head housing from the magnetic enclosure and free the cable.
  9. Carefully disassemble the sensors from the plastic blocks, discard the failed sensor assembly, and reassemble the new sensors into the plastic blocks. The old plastic blocks must be reused, because the sensor FRU does not contain plastic blocks.
    Note: Be careful not to touch the exposed sensor elements.
  10. Route the new cable through the magnet enclosure.
  11. Reposition each sensor head housing in its hole pattern on the magnet enclosure, and secure with the saved screws.
  12. Reconnect the RF body coil air flow sensor housing to the SRI.
  13. Replace the front end bell, split bridge, and side and skirt covers by reversing the procedures listed in Step 1 through Step 4.
  14. Remove LOTO. See the MR Service Safety Manual, PN 5452735.

Finalization

  1. Ensure that sensors are operating correctly. See Body Air Flow Functional Check.
  2. Ensure the laser light is aligned. See Laser Light Alignment.