Measurement Without Pressure Loss
The thermal mass measuring principle without moving parts enables accurate flow measurement with virtually no pressure loss and no wear.
CS Instruments – VA 550
Thermal mass flow sensor for installation in existing compressed air or gas pipelines from 3/4" to DN 1000.
| Measurement Type: Thermal Mass Flow Sensor |
| Installation: Insertion Type for 3/4" to DN 1000 |
| Pressure Range: Up to 50 bar (optionally up to 100 bar) |
| Media Temperature: -20 … 180 °C (ATEX: up to 120 °C) |
| Housing Protection: IP67 (ATEX II 2D: IP64) |
| Measuring Range: 1:1000 (0.1 to 224 m/s) |
| Accuracy: ±1.5% of reading ±0.3% f.s. (optional ±1.0%) |
| Outputs / Communication: 4–20 mA, Pulse; Modbus RTU/TCP, Ethernet, M-Bus, HART, IO-Link (optional) |
| Measurement Type: Thermal Mass Flow Sensor |
| Installation: Insertion Type for 3/4" to DN 1000 |
| Pressure Range: Up to 50 bar (optionally up to 100 bar) |
| Media Temperature: -20 … 180 °C (ATEX: up to 120 °C) |
| Housing Protection: IP67 (ATEX II 2D: IP64) |
| Measuring Range: 1:1000 (0.1 to 224 m/s) |
| Accuracy: ±1.5% of reading ±0.3% f.s. (optional ±1.0%) |
| Outputs / Communication: 4–20 mA, Pulse; Modbus RTU/TCP, Ethernet, M-Bus, HART, IO-Link (optional) |
- Thermal Mass Flow SensorMeasuring principle without moving parts, negligible pressure loss, robust sensor tip, and easy cleaning.
- Display of 4 Measurements + DiagnosticsThe display shows 4 values: flow rate, total consumption, velocity, and temperature. Diagnostic functions are available (e.g. errors and service information).
- Configuration and ServiceSettings and diagnostics via the display, PI 500 handheld unit, or service software; remote access via Modbus is also possible depending on the version.
- Installation Under PressureEasy installation and removal under pressure through a 1/2" ball valve; safety ring and insertion depth scale ensure correct positioning.
- Industrial DesignRobust aluminum housing with IP67 protection; all wetted parts are made of stainless steel.
- Standard Outputs1 × 4–20 mA analog output (non-isolated), pulse output, and RS 485 (Modbus RTU).
| Parameter | Low-Speed | Standard | Max | High-Speed |
|---|---|---|---|---|
| Measuring Principle | Thermal Mass Flow Sensor | |||
| Measuring Range (Flow Velocity) [m/s] | up to 50 | up to 92.7 | up to 185 | up to 224 |
| Measuring Range (Volumetric Flow) | Nm³/h – depends on pipe diameter and gas type (see measuring range table) | |||
| Reference Conditions | DIN 1343 (0 °C, 1013 mbar) | |||
| Accuracy (Standard) [% (r.v.) / % (f.s.)] | ±1.5% r.v. ±0.3% f.s. | |||
| Accuracy (Optional) [% (r.v.) / % (f.s.)] | ±1.0% r.v. ±0.3% f.s. | |||
| Accuracy Conditions | Ambient temperature 22 °C ± 2 °C, system pressure 6 bar | |||
| Repeatability [% (r.v.)] | 0.25 (with correct installation – position and inlet section) | |||
| Response Time (t90) [s] | < 3 | |||
| Ambient Temperature [°C] | –20 … +70 | |||
| Media Temperature [°C] | –20 … +180 (ATEX: –20 … +120) | |||
| Settings and Configuration | Via display, PI 500 handheld unit, PC service software, or remotely: Nm³/h, Nm³/min, Nl/min, l/s, ft/min, cfm, kg/h, kg/min, internal pipe diameter, reference conditions, zero adjustment, leak flow suppression, analog output scaling, pulse/alarm outputs, and error codes. | |||
| Outputs – Standard | 1 × 4–20 mA analog output (non-isolated), pulse output, RS 485 (Modbus RTU) | |||
| Outputs – Optional | 2 × 4–20 mA (active), Modbus TCP, HART, PROFIBUS DP, PROFINET, M-Bus, IO-Link | |||
| Load [Ω] | < 500 | |||
| Value Averaging | Freely adjustable averaging of all parameters from 1 minute to 1 day (e.g. 30-minute or daily average values) | |||
| Protection Rating | IP67 (ATEX II 2D: IP64) | |||
| Material | Die-cast aluminum housing; sensor tube: stainless steel 1.4404 | |||
| Mounting Thread | G 1/2" ISO 228; NPT 1/2", R 1/2", PT 1/2" | |||
| Operating Pressure [bar] | up to 50; special version up to 100 (DVGW version max. 16) | |||
| Power Supply | 18 … 36 V DC, 5 W | |||
| Certificates | ATEX II 2G Ex db IIC T4 Gb; ATEX II 2D Ex tb IIIC T90°C Db; DVGW | |||
Why Choose the VA 550?
Easy Installation Under Pressure
The insertion design allows installation and removal under pressure through a 1/2" ball valve – without shutting down the system or draining the pipeline.
Industrial Robustness and ATEX
Robust IP67 aluminum housing with all wetted parts made of stainless steel. ATEX versions are available for hazardous areas.
Wide Measuring Range and High Accuracy
Measuring range up to 1:1000 (up to 224 m/s) and accuracy up to ±1.0% of reading – suitable even for very low flow rates.
Advanced Communication and Integration
Supports 4–20 mA, pulse output, Modbus RTU/TCP, M-Bus, Ethernet, HART, IO-Link, and Profibus/Profinet for seamless integration into control systems.
Complete Flexibility and Diagnostics
Displays up to 4 values simultaneously (flow, consumption, velocity, temperature), with configurable gas type, reference conditions, and advanced diagnostics locally or remotely.
Energy
Energy MonitoringReliable measurement of air and gas flows to support energy monitoring and improve process efficiency.
Compressor Stations (FAD)
FAD MeasurementMeasurement of Free Air Delivery (FAD) directly in pipelines, even while the system remains in operation.
Chemical Industry
Process GasesAccurate flow measurement of technical gases for stable and safe chemical processes.
Food Industry (N₂ / CO₂)
Inert GasesMonitoring nitrogen and CO₂ consumption in packaging, cooling, and protective atmosphere applications.
Automotive Industry
Process AirReliable measurement of air and gas flow rates in manufacturing, assembly, and painting processes.
Aerospace Industry
Critical ProcessesHigh measurement accuracy for monitoring flows in demanding and safety-critical applications.
Metallurgy and Welding
Shielding GasesMeasurement of shielding and process gas flow rates for stable welding and metallurgical operations.
Natural Gas and Steam
Industrial MediaMonitoring industrial gas and process media flow rates for energy and technological applications.
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