Section 2 Installation
back pressure.
Following careful startup and venting procedures will contribute to a long
problem free life of your SLAMf53 controller.
Stable Operating Conditions:
As stated above, the SLAMf53 model utilizes a pressure operated main valve.
Valve performance is dependant on stable system pressures. Oscillating or
unstable upstream or downstream pressures are likely to cause the device
flow control to become unstable. For the best performance, it is important to
create a stable pressure environment by utilizing quality inlet and back pres-
sure regulators. In many cases, the addition of a back pressure regulator will
isolate the SLAMf53 from the unstable downstream pressures inherent in
many process designs.
All thermal mass flow controllers are factory tested with stable and equal
ambient and process temperatures. If the process temperature does not
equal the ambient temperature, the bypass ratio/accuracy will be affected.
When a hot or cold process fluid is being measured, ensure that the piping
system is designed to allow the gas temperature to equalize with the flow
controller ambient temperature.
For more information, please contact the Brooks Technical Service group.
Special Considerations to be taken when using Sanitary Fittings:
The maximum recommended product rating of 500 psi is based on pub-
lished product specifications of commonly available sanitary clamps. Brooks
does not supply sanitary clamps with the products. Customers shall select
the appropriate sanitary clamps and follow the manufacturers installation
instructions to achieve the needed pressure ratings.
Electrical Interface
The setpoint signal is supplied as a 0(1) to 5 Vdc, 0 to 10 Vdc, or 0(4)-20 mA
analog signal. All signals are supplied via the 15-pin Terminal Strip. For an
analog unit the minimum set of connections which must be made to the MFC
and MFM in13.5 - 27 Vdc, supply common, and a setpoint signal.
The Brooks Digital electrical interface is designed to facilitate
low-loss, quiet signal connections. Separate returns (commons) are supplied
for the analog setpoint, analog flow signal, and the power supply. These com
-
mons are electrically connected together on the PC board.
Analog I/O Versions
• Signal Common
• Signal Output (Voltage or Current)
• +13.5 - 27 Vdc Supply
• Setpoint Input (Voltage or Current)
• Setpoint Common
• Supply Common
• Chassis Ground (via unit body)
Refer to Figure 2-1 for pin connections
Refer to Figures 2-2 and 2-3 for electrical I/O connections
(The Brook’s MFC acts as a current sink to a setpoint input signal. The 0/4-20 mA
setpoint signal should be “driven” into the MFC input by a controlled current source.
Reference Brook’s device specifications for the setpoint input impedance.)
(The Brook’s MFC acts as the current source when providing a 0/4-20 mA output
signal to the load. The output signal is “driven” by the MFC into the customer load.
Reference Brook’s device specifications for maximum load capacity.)
24
