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you are using a pump of this type, it is recommended that a pulsation dampening device be used to
provide smooth continuous flow.
For liquid measurement systems using high pressure gas to force flow, the effects of the absorbed
gas must be considered. In these cases, sudden pressure drops up stream of the sensor such as line
size expansions, control valves, and pressure dropping regulators must be avoided. Sudden pressure
drops can cause the absorbed gas to release into the liquid, making the flow sporadic and difficult to
measure.
The ideal installation will provide the sensor with well established smooth flow, uniform
system temperature and consistent fluid media.
2.2
TRANSMITTER ELECTRONICS
The Rheotherm Flow Controller is available in 2 configurations, FCP and FCE.
Note: For best results it is recommended to set the setpoint withing 10-90% of the calibrated
flow range
FCP:
This version has a potentiometer adjustable setpoint. This is set to the specified flow rate
at the factory. To adjust the setpoint in the field, first open the cover, then turn the
potentiometer until the desired value is displayed on the screen. The cover should only be
opened in safe environments.
In this configuration the Flow Controller outputs a calibrated analog flow rate signal (0-
5V, 0-10V, 4-20mA) over the blue and white wires. White is positive and blue is ground.
FCE:
This version has an externally controlled setpoint. A 0-5 V analog input signal is sent
over the blue and white wires, with white as the signal wire and blue the ground. A PWM
signal will not work. When the flow controller is powered off, the external control signal
must also be powered off or the controller will draw power through the signal input line.
!! WARNING:
Connecting input wires to higher than 5 V (or less than 0 V) will void the warranty and damage the
instrument!
The instrument is designed to be watertight (non-submersible) when the covers are properly seated.
The housing(s) should be mounted such that wire/cable ports are located at the back, bottom, or sides
of the housing(s) to reduce risks associated with water spray, condensation and settling of dust and
dirt. All exposed parts are stainless steel (unless a special alloy has been specified), painted cast
aluminum or steel, polycarbonate, or quartz glass (display window) These materials tolerate most
corrosive environments.
Unless otherwise specified, normal ambient environment for the transmitter is 0-120
F.
