Saturday, January 13, 2018

How to Adjust Alarms and Pointer for Brooks Instrument Models MT3809G & MT3810G Variable Area Flowmeters

Here are the instructions for the removal and reinstallation of the XP housing indicator cover, and
how to adjust alarms and pointers for Brooks Instrument models MT3809G & MT3810G variable area flowmeters:

Warning: If it becomes necessary to service or remove the instrument from the system, power to the device is disconnected at the power supply.
  1. To begin make sure the float is at rest and there isn’t flow going through the meter.
  2. Using your hands or a strap wrench turn the cover counter clockwise to remove the cover from the housing.
  3. Remove the cover from the housing. The gasket should stay attached to the groove in the housing.
  4. Using a flat blade screwdriver with a 1/8" blade, hold the red alarm pointer and turn the screw counterclockwise to loosen the pointer, slide it to desired position on scale and tighten screw.
  5. Using a flat blade screwdriver with a 1/8" blade, hold the pointer and turn the screw to align with the “R” on the scale. It may take a few adjustments to get the pointer aligned to the “R”.
  6. To replace the cover, place the cover against the housing and turn the cover clockwise. Note, it will take several rotations to tighten the cover and the cover must be in contact with the gasket to keep a watertight seal.

MT3809G & MT3810G variable area flowmeter
Click for larger view.
For additional assistance, contact Flow-Tech in Maryland at 410-666-3200 or Virginia at 804-752-3450 or visit