Brooks Instrument 5850E - Manual (Page 26)

Brooks ® Model 5850E
3-6
Installation and Operation Manual
X-TMF-5850E-MFC-eng
Part Number: 541B102AAG
September, 2009
Section 3 Operation
factory setting. This is primarily caused by changes in temperature
between the 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.
To check zero, always mount the controller in its final configuration and
allow a minimum of twenty minutes for the temperature of the controller
and its environment to stabilize. Using a suitable voltmeter, check the
controller output signal. If it differs from the factory setting, adjust it by
removing the lower pot hole plug which is located closest to the controller
body. Adjust the zero potentiometer (refer to Figure 3-6) until the desired
output signal is obtained.
3-4 Calibration Procedure
Note 1: If the valve has been disassembled and any of the following parts
have been replaced, the control valve adjusting procedure in Section 4-4c
must be performed before the Model 5850E is calibrated.
orifice
valve stem
plunger
lower guide spring
valve seat
Note 2: Calibration of the Model 5850E 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.
Note 3: If the mass flow controller is to be used on a gas other than the
calibration gas, apply the appropriate sensor conversion factor. Size the
Figure 3-5 Model 5850E Calibration Connections