turck blog

Flow Monitors

TURCK 6/6/2018
 
TURCK Flow MonitorsTURCK flow monitors are solid-state devices that operate on the calorimetric or magnetic inductive principle. The monitors do not include any moving parts that may break or become lodged in the pipeline, as is often the case with mechanical devices that come in contact with the media being sensed.
 
WHY CHOOSE TURCK FLOW MONITORS?
 
 • Choice of monitor to suit specific application needs: Inline models, self-contained devices or remote probe styles (with a separate signal processor).
 • Rugged design; most monitors are rated for IP67 protection.
 • All wetted parts are made of stainless steel, titanium, Hastelloy or PVDF.
 • Select models designed to withstand caustic materials.
 • Pressure ratings of up to 1450 psi on select models.
 • Calometric flow monitors have a temperature gradient of 4°C/sec, which allows them to respond rapidly to changes in flow.
 
WHERE CAN I USE TURCK FLOW MONITORS?
 
Any application that requires monitoring water, oil, inert gases and air flow. In applications with a larger pipe or long standoff, probes are available in 20 millimeter increments with a maximum length of 220 millimeters.
 
 • Pump run dry protection
 • Dosing monitoring/verification
 • Industrial ventilation
 • Filtration systems
 • Lubrication monitoring
 • Cooling systems
 • Welders
 • Power transformers
 • Laser systems
 • Molding
 • Casting
 
WHAT IS THE FCMI FLOW MONITOR?
 
TURCK Flow MonitorsThe FCMI magnetic inductive flow monitor was designed for measuring electrically conductive liquids using Faraday’s inductive measuring principle. Electrons in the fluid are driven to the pipe wall when passing through the magnetic field created in the measuring pipe. This causes a potential difference that is detected by two laterally mounted electrodes. Based on the known magnetic field and the electrode spacing, the measured potential difference at the electrodes is proportional to the flow speed and therefore the flow rate.
 
WHY CHOOSE THE FCMI FLOW MONITOR?
 
 • The FCMI is completely wear-free, because it has no moving parts. In contrast to monitors that employ other measuring principles, FCMI monitors do not require a reduction of the pipe diameter and do no obstruct the flow of the medium.
 • Easy-to-use push buttons for programming the monitor are password protected to prevent inadvertently altering flow settings.
 • Measuring accuracy: 2% of the measured value
 • Available with 1 switching output and linear 4-20 mA analog output
 
WHERE CAN I USE FCMI FLOW MONITORS?
 
 • Ideal for applications with low to medium flow rates up to 20 gpm in a 3/4” pipe.
 • Electrically conductive fluids, i.e. water/water based fluids:
 • Minimum conductivity: 10 µS/cm For example: water =15µS/cm
 
TURCK Flow Monitors
 
FCMI monitors utilize Faraday’s magnetic inductive principle
 
TURCK Flow Monitors
 
FCMI monitors may be secured using the four M4 threaded holes located on the bottom of the housing. An optional mounting plate (pictured above) may be used for applications that use flexible tubing. Compression fittings and NPT adapters are also available.
 
WHAT IS THE FTCI FLOW MONITOR?
 
The FTCI inline flow monitor is a self-contained, solid-state, fully programmable sensor that monitors both flow and temperature. The monitor operates using the calorimetric flow principle, which detects the transfer of heat in thermally conductive fluids. The temperature detecting elements are platinum RTDs. One of the elements (R1) detects the temperature of the fluid in the pipe and the resistor (R2) is connected to a heater. The heating element heats R2 to a temperature that is slightly above the temperature of the surrounding fluid. When there is no fluid flow, the difference between R1 and R2 remains constant. As the fluid moves through the sensor, heat is conducted away from the heated element causing the temperature of R2 to decrease. This heat loss causes the differential resistance input to the amplifier where the various outputs are generated.
 
WHY CHOOSE THE FTCI FLOW MONITOR?
 
 • Rugged design implements stainless steel wetted parts and mounts directly into the pipeline.
 • Highly visible three-digit display that can alternate between flow rate and media temperature.
 • High repeatability; able to monitor changes in flow as low as 0.2 gallons per minute (gpm) or as fast as 12 gpm.
 • Easy-to-use push buttons for programming the monitor are password protected to prevent inadvertently altering flow settings.
 • Two outputs to monitor flow rate, or one output for flow rate and one output for temperature.
 • Programmable on and off time delay functions.
 • User defined hysteresis for both the flow and temperature set points.
 • Programmed to perform in many different media.
 • Water
 • Deionized water
 • Ethylene glycol (0-70%)
 • If the fluid is a glycol/water mix, the percentage of glycol can be programmed so that the monitor can adjust to each unique application without the need for factory calibration. 
 • Can be programmed for liters per minute or gallons per minute, as well as °F or °C.
 • An adjustable filter to smooth out a variety of erratic flow conditions.
 • Pressure resistance of 145 psi.
 
WHERE CAN I USE THE FTCI FLOW MONITORS?
 
 • Weld tip protection
 • Transformer cooling
 • Process chamber cooling
 • Hot roller coolant
 • Cooling water monitor
 
TURCK Flow Monitors
 
FTCI monitors are available with different fluid connections and accessories. It is manufactured with a standard eurofast M12 connector.
 
WHAT IS THE FCI INLINE FLOW MONITOR?
 
TURCK Flow MonitorsThe FCI inline flow monitor operates using the calorimetric flow principle, which detects the transfer of heat in thermally conductive fluids. The temperature detecting elements are platinum RTDs. One of the elements (R1) detects the temperature of the fluid in the pipe and the resistor (R2) is connected to a heater. The heating element heats R2 to a temperature that is slightly above the temperature of the surrounding fluid. When there is no fluid flow, the difference between R1 and R2 remains constant. As the fluid moves through the sensor, heat is conducted away from the heated element causing the temperature of R2 to decrease. This heat loss causes the differential resistance input to the amplifier where the various outputs are generated. With FCI flow monitors, the temperature elements are bonded directly to the outside of a flow through tube. See probe section for more information about the calormetric flow monitors.
 
WHY CHOOSE THE FCI INLINE FLOW MONITOR?
 
 • No pressure loss
 • Wide range of flow rates
 • Fast response time
 • Low flow rate detection and pulsed flow monitoring.
 • Stackable
 • Viscous fluids can flow freely through the fully ported sensor, since the flow does not need to be disrupted to be detected.
 
WHERE CAN I USE THE FCI INLINE FLOW MONITOR?
 
 • Flow/no flow
 • Dispensing applications
 • Viscous fluids
 • Low and/or pulsing flows
 • Set point applications
 
TURCK Flow Monitors
 
The resistance difference is measured by a Wheatstone bridge circuit. A change in resistance difference causes a change in bridge voltage. The flow set point is determined by comparing the bridge voltage to a reference voltage.
 
TURCK Flow Monitors
 
Setup – Operating and Display Functions
 
Self Contained Inline
TURCK Flow Monitors
 
TURCK Flow Monitors
 
WHAT IS A FCS PROBE STYLE FLOW MONITOR?
 
Probe style flow monitors detect the speed of liquids and gases without using mechanical parts. These solid state flow monitors operate on the calorimetric principle: the measure of heat transfer from an object to a fluid.
 
TURCK Flow MonitorsThe TURCK solid state flow monitors use two temperature dependent resistors. One of the resistors (R1) monitors the temperature of the surrounding fluid. The other resistor (R2) is connected to a heating element. The heating element heats R2 to a temperature that is slightly above the surrounding fluid temperature. When there is no fluid flow, the difference in resistance between R1 and R2 is a fixed value. As fluid moves over the flow monitor probe, heat is conducted away from the heating element causing the temperature on R2 to decrease. This heat loss changes the difference in resistance between R1 and R2.
 
The resistance difference is measured by a Wheatstone bridge circuit. A change in resistance difference causes a change in the bridge voltage. The flow set point is determined by comparing the bridge voltage to a reference voltage.
 
TURCK Flow Monitors
 
Operating Range
 
Heat loss on the heating element will likewise determine the sensitivity of the monitor. The heat loss becomes a function of flow velocity and thermal conductivity of the fluid. The lower the thermal conductivity of the fluid, the faster the fluid has to flow to be detected.
 
Flow monitor operating ranges vary from one type of fluid to another. These operating ranges are proportional to the speed of the fluid that the monitor can detect. For example, at the same flow rate, air can conduct only a fraction of the heat away from the heating element compared to water.
 
Response Time
 
The switch-on time is the time required for the flow monitor to detect and indicate that the flow speed is increasing. The switch-off time is the time required for the flow monitor to detect and indicate that the flow speed is decreasing.
 
Time Delay Before Availability
 
The availability is the time required, after power has been applied, for the flow monitor to reach a stable operating condition. The availability provides the time needed to energize the flow monitor and for the flow monitor to stabilize at the fluids temperature.
 
Effects of Housing Material
 
The response time and temperature gradient is dependent on the housing material. Flow monitors that use Teflon have a low thermal conductivity causing a slower response time to fluid temperature changes and to changes in the flow speed.
 
WHY CHOOSE A FCS PROBE STYLE FLOW MONITOR?
 
Temperature Gradient
 
The temperature gradient of a fluid indicates the change in fluid temperature within a specified time (unit of easure: °C (°F)/min). The temperature gradient of a device defines the maximum temperature rise that can be compensated by the monitor without malfunction.
 
The monitor has the ability to compensate for sudden thermal shifts within the specified extremes. Sudden temperature changes exceeding the specified tolerances (temperature error) may cause the device to malfunction. Only when the monitor has adapted to the new temperature, will it provide an accurate measurement. The temperature gradient for TURCK flow monitors is 4°C/second. This is 15 times higher than standard flow devices, which makes for a particularly accurate switch-point stability during variations in temperature. The sensitivity to temperature rise of TURCK flow monitors has been reduced to a minimum (<12 s) and can accurately be determined in advance.
 
TURCK Flow Monitors
 
Graph 1 can be used to determine if the TURCK flow monitor can compensate for a temperature change to a sensed medium. The dotted line in the graph indicates that a 10°C change has occurred in a time period of 5 seconds. Points (5,10) intersect in the “No False Output” region of the graph. This example illustrates an acceptable degree of temperature change in the application. As a result, the flow monitor can compensate for the fluid temperature change. Fahrenheit = (1.8X°C) + 32
 
WHERE CAN I USE A FCS PROBE STYLE FLOW MONITOR?
 
 • Large pipes: probe lengths available for up to 220 mm
 • Flow/no flow detection
 • Set point applications
 • Linear analog for water applications
 • High pressure, intrinsically safe, plastic versions
 • Pump run dry protection
 
Mounting Instructions
 
Areas of turbulent flow occur whenever there is a change in the pipe construction (e.g. pipe inlets, pipe outlets, pipe elbows). To avoid an inaccurate output, the following guidelines should be observed:
 
TURCK Flow Monitors
 
Setup – Operating and Display Functions
 
TURCK Flow Monitors
 
WHAT IS A FCS FLOW MONITOR?
 
A compact flow sensor for monitoring gaseous media. It is available in two versions: one that includes the sensor and signal processing unit in a single housing for local adjustment and display, and another where the sensors and signal processing unit are separated for remote monitoring purposes. In the case of the latter, the processer is housed in the control cabinet.
 
TURCK Flow Monitors
 
WHY CHOOSE A FCS FLOW MONITOR?
 
 • Easy adjustment via potentiometer
 • Transistor, relay or current output
 • Insertion principle:
 • Pressure resistance up to 30 bar
 • Adjustable range between 0.5 m/s and 30 m/s
 • Inline principle
 • No pressure loss
 • Response time within seconds
 • Adjustable range between 0.5 m/s and 40 m/s
 
WHERE CAN I USE A FCS FLOW MONITOR?
 
 • Monitors that operate using the insertion principle are suited for most pipes.
 • Monitors that operate using the inline principle are ideal for low flow rates and pipe diameters of up to 3/8”.
 
Mounting Instructions
 
TURCK Flow Monitors