Liquid Vortex Flow Sensor Features High Accuracy and Low Cost
Description
Clark Solutions announces the availability of a new family of liquid vortex flow sensors. DN Series Vortex Flow Sensors are designed specifically for equipment manufacturers as an excellent choice for system flow monitoring and control. Combining both high accuracy and low cost, DN Series Flow Sensors are accurate to 1% fs of measured value. Suitable for water & water glycol based heat exchange systems (with the usual additives) and other fluids, current DN Series models are suitable for flow ranges from 0.9 to 150 liters per minute (0.24 to 39.6 GPM).
DN Series Liquid Vortex Flow Sensors operate on the principle of Kármán’s vortex trail. Named after Theodore von Kármán's mathematical description of the phenomenon, vortex-shedding flow meters present the flow in a pipe with an obstruction/bluff in the flow meter body. As velocity increases, alternating vortices are formed on each side of the bluff body and travel downstream. DN series flow sensors utilize piezoelectric sensors embedded in an ETFE vane located downstream of the bluff to detect the generated vortices. The frequency measured represents the flow velocity. The result is a temperature insensitive measurement of flow with minimal pressure loss. A flow factor is provided to convert frequency to volume flow rate for each model size. Versions with a 1000 Ohm RTD temperature sensor built-in to the bluff are available, providing direct temperature measurement in the medium.
DN Series Liquid Vortex Flow Sensors operate on the principle of Kármán’s vortex trail. Named after Theodore von Kármán's mathematical description of the phenomenon, vortex-shedding flow meters present the flow in a pipe with an obstruction/bluff in the flow meter body. As velocity increases, alternating vortices are formed on each side of the bluff body and travel downstream. DN series flow sensors utilize piezoelectric sensors embedded in an ETFE vane located downstream of the bluff to detect the generated vortices. The frequency measured represents the flow velocity. The result is a temperature insensitive measurement of flow with minimal pressure loss. A flow factor is provided to convert frequency to volume flow rate for each model size. Versions with a 1000 Ohm RTD temperature sensor built-in to the bluff are available, providing direct temperature measurement in the medium.
Specs
• Medium: Suitable for water & water glycol based heat exchange systems with the usual additives and other • fluids compatible with the materials of construction (consult factory). For media with viscosity greater than • 2 millipascal seconds (2 centipoise), higher flow rates are required to form vortices raising the minimum • measurable flow rate value. • Flow ranges: From 0.24 to 39.6 GPM (0.9 ... 150 litres per minute). See model table 1. • Temperature measurement: Optional PT1000 RTD imbedded in flow sensor bluff o Measure range -40°F to +302°F (-40 to > +150 °C) o 1000.00 Ohm @ 32°F (0°C) o 1573.25 Ohm @ 302°F (150°C) • Temperature: Ambient: 5° to185°F (-15 to + 85°C) o In storage: -22° to 185°F (-30 to + 85°C) • Max. test pressure: 261 psi/18 bar at 104°F/40°C • Loss of pressure / cavitation: A minimum inlet pressure of 10.2 psi (0.7 bars) is required to avoid cavitation • issues at maximum flow. • Wetted materials: • Sensor vane: ETFE • Sealing material: EPDM • Flow sensor and bluff: o ASTM- PPA, Polyphthalamide o ISO-PA6T/6I, Grivory 40%GF • Power supply:5 VDC (4.75 to 5.25) • Output: Square pulse frequency 0 / 5 VDC (The signal frequency depends on the nominal diameter, see order) • Signal amplitude at UIN=5.0 V:Load > 10 kOhm against IN < 0.1 … 5.0 V • Current consumption: < 4 mA • Response time: A high accuracy of flow rate is detected within 100 ms. • Electrical connection: 3-pole connector (without temperature output), RAST 2.5 (AMP DUO PLUG • 2.5™ is recommended mating connector.) M12x1, 5-pole circular receptacle provided for temperature • output option. See accessories for cable assembly offerings • Polarity reversal protection: Mechanically protected • Protection class: IP20, IP65 (M12x1 only) • Mounting position: In principle universal. We recommend that, when the sensor is mounted in • horizontal pipe runs that the electrical connection/sensor assembly be mounted off vertical • (3 o'clock or 9 o'clock best). • Piping connection fittings: See tables 4-6 for standard selection of types & sizes. Special fittings • can be produced by Clark or the customer. • Accuracy: Accuracy specifications are valid for media with a viscosity <2 centipoise (2 millipascal seconds): o For water in temperature range 41 to 212°F (5 to 100°C) or for water with maximum 20% glycol at >77°F (>25°C) o Up to 50% fs: < 1% fs o From 50% fs: < 2% of measured value • Temperature measurement accuracy: • PT 1000 for DIN EN 60751 Class B o ± 0.8°F @ 68°F (± 0.45°C @ 20°C) o ±1.4°F @ 190°F (± 0.75°C @ 90°C) • Weight (Without End Fittings): o DN 8 approx. 0.10 lbs (47 g) o DN 10 approx. 0.13 lbs (57 g) o DN 15 approx. 0.15 lbs (68 g) o DN 20 approx. 0.20 lbs (92 g) o DN 25 approx. 0.22 lbs (100 g) • Packaging: • Packaged singly (standard) or in multiple blister packs • Blister packs: • DN 8, 10 and 15 Blister packs each containing 30 pcs • DN 20 and 25 Blister packs each containing 20 pcs