Overview

The EE741 is a modular, compact inline flow meter designed for precise measurement and monitoring of compressed air and technical gases (e.g., O2, N2, Ar, CO2) in pipe diameters DN15 to DN50. It uses a thermal measurement principle with a proven hot-film sensor element, ensuring high long-term stability and fast response.

Measurement Principle and Performance

• Thermal hot-film sensor technology for accurate flow measurement.
• Multi-point calibration under 7 bar pressure guarantees excellent accuracy, especially at low flow rates, enabling early leak detection.
• Measurement ranges vary by pipe diameter, from 0.2 to 848.2 m³/h (air at standard conditions).
• Accuracy: ±(3% of reading + 0.3% full scale) at 7 bar abs and 23 °C.
• Temperature dependence: ±0.25% per °C deviation from 23 °C.
• Pressure compensation possible via system pressure input; otherwise ±0.5% per bar deviation from 7 bar.
• Response time t90 < 2 seconds; measurement interval 0.1 seconds.

Modular Design and Installation

• Sensor compatible with three different pipe diameters per model.
• Sensor can be installed or removed without cutting the pipeline, ideal for temporary measurements.
• Available measurement blocks in aluminum or stainless steel, with threaded or flange connections.
• Pipe diameters supported: DN15, DN20, DN25 (standard); DN32, DN40, DN50 (flanged version EE741-N50).

Calibration and Certification

• Calibration traceable to the International System of Units (SI).
• Calibration performed by E+E Elektronik GmbH's accredited laboratory (DIN EN ISO/IEC 17025, ID 0608).
• Certificates available for humidity, temperature, dew point, air velocity, flow, pressure, and CO2.
• Information and certificate requests available at www.eplusecal.com.

Display and User Interface

• Displays instantaneous flow and total consumption.
• Intuitive configuration via display buttons or free EE-PCS software.
• Display rotates in 90° increments for optimal readability in any installation orientation.

Interfaces and Outputs

• User-configurable via display or software.
• Analog output: 0-20 mA or 4-20 mA (load < 500 Ω).
• Two configurable switching outputs (PNP, max 100 mA, configurable as normally open/closed, hysteresis, window).
• Pulse output for consumption measurement (pulse length 0.02 to 2 s).
• Digital communication: Modbus RTU (RS485), M-Bus, IO-Link (v1.1, COM2, 38.4 kBaud).

Measured Parameters and Units

• Norm volume flow (m³/h, m³/min, l/min, l/s, SCFM).
• Mass flow (kg/h, kg/min).
• Norm velocity (m/s, SFPM).
• Temperature (°C, °F).
• Consumption counter for cost-effective analysis without additional data logger.

Technical Specifications

• Operating pressure up to 16 bar (PN16).
• Operating temperature range: with display 0 to +50 °C; without display -20 to +60 °C.
• Medium temperature and storage: -20 to +60 °C.
• Humidity: 0 to 100% RH, non-condensing.
• Materials: Sensor housing - polycarbonate; sensor head - stainless steel 1.4404/glass; measurement block - anodized aluminum or stainless steel 1.4404; flange version entirely stainless steel 1.4404.
• Ingress protection: IP65.
• Electromagnetic compatibility: EN 61326-1, EN 61326-2-3 (industrial environment), FCC Part15 Class A, ICES-003 Class A.

Mechanical Dimensions

Detailed dimensions provided for measurement blocks with threaded (Rp or NPT) and flange connections for all supported pipe sizes (DN15 to DN50). Flanged blocks designed for robust industrial applications with full stainless steel wetted surfaces.

Ordering Information

• Hardware configuration includes pipe diameter, output type (analog, digital, switching, pulse), display option, accessories, and cleaning (oil- and grease-free cleaning for oxygen measurement).
• Software setup allows selection of pipe diameter, output signals, measured parameters, units (SI or US), and medium type (air or other gases).
• Measurement blocks ordered separately by material (aluminum or stainless steel), connection type (BSP, NPT, flange), and pipe diameter.
• Example order: EE741-A6D2AC2DN15 (sensor unit with analog/switch/pulse outputs, display with backlight, M12 connector, DN15 pipe diameter) plus HA079015 (aluminum DN15 BSP threaded measurement block).

Accessories and Spare Parts

• Inlet/outlet straight sections in stainless steel for all pipe sizes.
• Gasket sets for flanged measurement blocks.
• Shielded sensor connection cables with M12x1 connectors.

Manufacturer and Support

Produced by E+E Elektronik Ges.m.b.H., Austria, with subsidiaries worldwide providing sales and technical support.

Critical Information and Best Practices

• Ensure correct selection of pipe diameter and measurement block for accurate readings.
• Use oil- and grease-free cleaning (AF2) when measuring oxygen to avoid contamination.
• Configure pressure compensation via software for improved accuracy under varying system pressures.
• Regular calibration recommended; sensor can be removed without pipeline interruption for maintenance.
• Do not mix SI and US units in configuration.