Brooks Instrument 5861i - Manual (Page 27)

4-3
Installation and Operation Manual
X-TMF-5861i-MFC-eng
Part Number: 541B111AAG
November, 2008
Brooks ® Model 5861 i
Section 4 Maintenance
2. Verify that the process gas connections have been correctly terminated
and leak checked.
B. Bench Troubleshooting
1. Properly connect the mass flow controller to a +15 to +28 Vdc power
supply, and connect an output signal readout device (4-1/2 digit
voltmeter recommended) to (Pins 2 and 10 D-connector) (Refer to
Figure 2-2). Apply power, and allow the flowmeter to warm up for 45
minutes. Do not connect to a gas source at this time. Observe the
output signal and, if necessary perform the zero adjustment
procedure (Section 3-3). If the output signal will not zero properly,
refer to the sensor troubleshooting section and check the sensor. If
the sensor is electrically functional, the printed circuit board is
defective and will require replacement.
2. Connect the flowmeter to a source of the gas on which it was
originally calibrated. Increase the flow until 100% indication
(5.00Vdc) is achieved. Vary the flow rate over the 2 to 100% range
and verify that the output signal follows the flow rate. If possible,
connect a flow measurement device in series with the mass
flowmeter to observe the actual flow behavior and verify the
accuracy of the mass flowmeter. If the mass flowmeter functions as
described above, it is functioning properly and the problem may lie
elsewhere.
Table 4-1 lists possible malfunctions which may be encountered during
bench troubleshooting.
C. Sensor Troubleshooting
If it is believed the sensor coils are either open or shorted, troubleshoot
using Table 4-2. If any of the steps do not produce the expected results the
sensor assembly is defective and must be replaced. Refer to Section 4-4
for the disassembly and assembly procedures to use when replacing the
sensor.
Note: Do not attempt to disassemble the sensor.
Cleaning Procedures
Should the Model 5861 i Mass Flowmeter require cleaning due to
deposition, use the following procedures:
1. Remove the unit from the system.
2. Refer to Section 4-4 to disassemble the meter.