Brooks Instrument 5850EM - Manual (Page 41)

3-17
Brooks ® Models 5964, 5850EM
Section 3 Operation Installation and Operation Manual
X-TMF-5964-5850EM-MFC-eng
Part Number: 541B121AHG
November, 2008
3-7 Calibration Procedure
If the valve has been disassembled and any of the following parts have
been replaced, the control valve adjusting procedure in Section 4-4 must
be performed before the Model 5964/5850EM is calibrated.
-orifice -lower guide spring
-valve stem -valve seat
-plunger assembly
Calibration of the Model 5964/5850EM mass flow controller requires the
use of a digital voltmeter (DVM) and a precision flow standard calibrator
such as the Brooks Instrument’s Vol-U-Meter. It is recommended that the
calibration be performed only by trained and qualified service personnel.
The recommended flow circuit for performing zero, adjustments, calibration
and troubleshooting is shown in Figure 3-13.
If the mass flow controller is to be used on a gas other than the calibration
gas, apply the appropriate gas conversion factor, (Refer to Section 4-5).
Size the orifice for actual operating conditions (Refer to Section 4-6).
If older Brooks’ secondary electronics, Models 5878, 5876 and 5896, are
being used as a power supply during the calibration, the 5 Volt reference
must be enabled on the card edge version for proper operation. Remember
to deactivate the 5 Volt reference before installing the calibrated mass flow
controller in the system where Terminal 10 is grounded.
Do not ground 5 Volt reference output when it is enabled.
Improper operation of the printed circuit board will result.
CAUTION
There are three fundamentally different printed circuit boards used on the
Model 5964/5850EM depending on line pressure and full scale flow rate.
The enhanced response PC Board is the primary board and is used for all
Nitrogen equivalent full scale flow rates above 50 sccm with line pressures
less than 150 psig. The settling time specification for the enhanced
response PC Board is one second. The second type of PC Board is the
standard response PC Board with a settling time of three seconds. The
enhanced response PC Board can be identified by five adjustment
potentiometers versus four potentiometers on the standard response PC
board. The third type of PC Board is the Current I/O version which also has
a settling time of three seconds.
Figure 3-13 Bench Troubleshooting Circuit