PWE paddlewheel meter for liquid flow measurement.
Principles of Operation
Liquid flowing through the unit causes the paddle wheel to spin. As the magnets embedded in the paddle wheel spin past the sensor, electrical pulses are produced in which the frequency is proportional to the flow rate. The number of pulses per desired time interval and the K-factor (number of pulses/Gallon) make it is possible to calculate the flow rate and volume passing through the unit. On board CPU and signal conditioner circuitry perform accurate flow and total computation, digital communication and provide analog 0-5 Vdc or 4-20 mA output signals. Non-volatile memory stores all hardware specific and ser programmable variables, including flow linearization table. The flow rate can be displayed in 23 different volumetric or ass flow engineering units. Flow meter parameters and functions can be programmed locally via key pad and LCD* or remotely via the RS-232/RS-485 interface. PWE flow meters support various functions including: two independently programmable flow totalizers, user programmable low, high or range flow and temperature* alarm, two sets of user programmable optically isolated outputs, self diagnostic alarm, flow pulse output. Optional local 2×16 LCD* readout with adjustable back light provides flow rate, temperature*, total volume reading in currently selected engineering units, diagnostic events indication and feature a password protected access to the process parameters to ensure against tampering or resetting.
|FLOW MEDIUM Please note that PWE Flow Meters are designed to work only with liquids. Never try to measure flow rates of dry gas.|
|CALIBRATIONS Performed at standard conditions [14.7 psia (101.4 kPa) and 70°F (21.1°C)] unless otherwise requested or stated.|
|VISCOSITY Calibrated to 1 cSt (water). Meters with display can be used for fluids up to 50 cSt with field calibration (maximum flow range may be affected).|
|ENVIRONMENTAL (PER IEC 664) Installation Level II; Pollution Degree II.|
|FLOW ACCURACY (INCLUDING LINEARITY) ±1% of FS|
|REPEATABILITY ±0.25% of full scale.|
|FLUID TEMPERATURE MEASURMENT RANGE* -10 to 70 °C|
|TEMPERATURE ACCURACY (INCLUDING LINEARITY)* ±0.5 °C|
|FLOW RESPONSE TIME approximately 1 seconds (above 10% of full scale flow), approximately 2 seconds (below 10% of full scale flow)|
|MAXIMUM PRESSURE 10 bar (150 psi)|
|MAXIMUM PRESSURE DROP 1.4 bar (20 psi) at 132.5 L/min flow. See Table IV for pressure drops associated with various models and flow rates.|
|FLUID AND AMBIENT TEMPERATURE 14°F to 160°F (-10°C to 70°C)|
|OPTICALLY ISOLATED OUTPUTS UCE @ 40Vdc, ICE @ 150 mA|
|FLOMETER INPUT POWER 11 to 26 Vdc, 100 mV maximum peak to peak output noise
Circuit board have built-in polarity reversal protection, 300mA resettable fuse provide power input protection.
|COMMUNICATIONS PARAMETERS (RS-232/RS-485)
|DISPLAY* Optional local 2×16 characters LCD with adjustable backlight (2 lines of text).|
|KEY PAD* Optional 4 push button key pad.|
|CE COMPLIANCE EMC Compliance with 89/336/EEC as amended.
Emission Standard: EN 55011:1991, Group 1, Class A
Immunity Standard: EN 55082-1:1992