Brooks Instrument 5851EM - Manual (Page 33)

3-7
Brooks ® Models 5965, 5851EM
Section 3 Operation Installation and Operation Manual
X-TMF-5965-5851EM-MFC-eng
Part Number: 541B122AAG
September, 2009
Figure 3-6 Model 5851EM Calibration Connections
Note 5: when calibrating the current l/o Version, it is easiest to calibrate
using 0-5 vdc command and flow signals. Refer to section 2, Figures 2-4,
2-6 and 3-5 for proper hookups. After calibration, the Model 5965/5851EM
may be reconfigured for Current l/O operation with negligible change in
calibration.
a. with the controller installed in an unpressurized gas line, apply power
and allow approximately 45 minutes for warm-up. During the warm-up,
adjustment and calibration check procedures do not allow the control
valve to open when gas flow is not present. This situation is not a
normal operating mode and will cause abnormal heat-up of the control
valve. with this abnormally warm valve, the meter will be difficult to
calibrate. This situation can be prevented by switching the valve
override "closed" when there is no gas flow or by setting the command
to less than one percent (1%). Also, avoid unnecessary periods with the
valve override "open".
Note: For Model 5965/5851EMs with normally open valves this condi-
tion can be prevented by switching the valve override "open" or by
setting the command to 100% when there is no gas flow. Also, avoid
unnecessary periods with valve override "closed".