Brooks Instrument 5861i - Manual (Page 18)

3-2
Installation and Operation Manual
X-TMF-5861i-MFM-eng
Part Number: 541B111AAG
November, 2008
Brooks ® Model 5861 i
Section 3 Operation
3-2 Operating Procedure
a. Apply power to the flowmeter and allow approximately 45 minutes for
the instrument to warm-up and stabilize its temperature.
b. Turn on the gas supply.
c. Shut-off flow to the meter and observe the flowmeter's output signal.
If the output is not 0mVdc (±10mVdc), check for leaks and if none
are found, refer to the re-zeroing procedure in Section 3-3.
d. Open valve to allow flow to pass through the meter. Monitor the flow
output signal.
3-3 Zero Adjustment
Each Model 5861 i is factory adjusted to provide a 0mVdc ±10mVdc signal
at zero flow. This will equate to a 4mA or 0mA current output depending no
the jumper selection. After initial installation and warm-up in the gas
system the zero flow indication may be other than the factory setting. This
is primarily caused by changes in temperature between our calibration
laboratory and the final installation. The zero flow reading can also be
affected to a small degree by changes in line pressure and mounting
attitude.
Figure 3-1 Flow Sensor Operational Diagram