Reference Measurement Accuracy
Highly accurate reference flow meter based on a Venturi tube according to ISO 5167-3. Achieves accuracy up to ±0.5% of reading in the range from 0.2 Qmax to Qmax.
CS Instruments – CMM 500
Reference flow meter for compressor performance measurement and compressed air billing. Venturi technology according to ISO 5167-3 provides exceptional accuracy, a wide measuring range, and minimal pressure loss.
| Measuring Principle: Venturi, differential pressure (ISO 5167-3) |
| Accuracy: up to ±0.5% of reading |
| Measuring Range: 1 : 130 |
| Response Time: < 1 s |
| Medium Temperature: -20 … +100 °C |
| Operating Pressure: up to 16 bar(g) (optional 30 / 100 bar) |
| Power Supply: 18 … 36 VDC |
| Outputs / Communication: 4–20 mA, pulse, Modbus RTU (optional Ethernet/PoE, M-Bus) |
| Measuring Principle: Venturi, differential pressure (ISO 5167-3) |
| Accuracy: up to ±0.5% of reading |
| Measuring Range: 1 : 130 |
| Response Time: < 1 s |
| Medium Temperature: -20 … +100 °C |
| Operating Pressure: up to 16 bar(g) (optional 30 / 100 bar) |
| Power Supply: 18 … 36 VDC |
| Outputs / Communication: 4–20 mA, pulse, Modbus RTU (optional Ethernet/PoE, M-Bus) |
- Basic CMM 500 ConfigurationReference Venturi flow meter for compressed air and gases. The final configuration is determined by selecting the measuring section, flange type, display, signal outputs, and, if required, inlet and outlet sections.
| Parameter | DN 50 | DN 80 | DN 100 | DN 125 | DN 150 | DN 200 |
|---|---|---|---|---|---|---|
| Measuring Medium | Air, gases | |||||
| Measuring Principle | Differential pressure, Venturi | |||||
| Measuring Range | 1 : 130 | |||||
| Accuracy (Qmin to 0.2 Qmax) [% (of reading)] | ± 1 | |||||
| Accuracy (0.2 Qmax to Qmax) [% (of reading)] | ± 0.5 | |||||
| Typical with inlet/outlet sections (Qmin to 0.2 Qmax) [% (of reading)] | ± 0.75 | |||||
| Typical with inlet/outlet sections (0.2 Qmax to Qmax) [% (of reading)] | ± 0.3 | |||||
| Response Time (t99) [s] | < 1 | |||||
| Medium Temperature [°C] | -20 … +100 | |||||
| Operating Pressure [bar(g)] | max. 16 (optional 30 / 100) | |||||
| Ambient Temperature [°C] | -30 … +70 | |||||
| Power Supply [VDC] | 18 … 36 | |||||
| Signal Outputs (Standard) | RS-485 (Modbus RTU), 4–20 mA, pulse output | |||||
| Signal Outputs (Optional) | Ethernet interface, M-Bus | |||||
| Process Connection | DIN EN 1092-1 flange or ANSI flange | |||||
| Installation Conditions | In horizontal pipelines or vertical risers | |||||
Why Choose the CMM 500?
Extremely Wide Measuring Range
A large measuring range of 1:130 enables reliable measurement of both very low and very high flow rates without sacrificing accuracy.
Wet and Dry Compressed Air Measurement
Suitable for measuring wet compressed air directly downstream of compressors as well as dry compressed air for consumption monitoring and billing.
Minimal Pressure Loss
Venturi technology provides extremely low pressure loss (less than 70 mbar at maximum flow), reducing energy losses and improving system efficiency.
No Moving Parts
The meter contains no moving parts, eliminating bearing wear and sensitivity to particles commonly found in turbine meters and mechanical gas meters.
Maintenance During Operation
Thanks to the integrated valve block, zero adjustment, condensate drainage, and sensor replacement for calibration can all be performed without shutting down the system and while under pressure.
Fast Response and Peak Detection
An extremely short response time (< 1 s) enables accurate detection of load peaks and flow changes without delay.
Extensive Communication Options
Available interfaces include 4–20 mA outputs, pulse output, Modbus RTU, Modbus TCP, Ethernet (PoE), and M-Bus.
Manufacturing Industry
Compressed AirAccurate monitoring of compressed air generation and consumption in production facilities for cost optimization, process stability, and internal consumption allocation.
Automotive Industry
High AccuracyReliable flow measurement for compressor station monitoring, energy analysis, and ensuring consistent quality in automotive manufacturing.
Food and Beverage Industry
Energy MonitoringCompressed air consumption measurement for compressor optimization, leak reduction, and support of energy management programs.
Chemical and Pharmaceutical Industry
Process ReliabilityHighly accurate flow measurement in demanding process environments where supply stability, traceability, and long-term measurement reliability are essential.
Metal Processing Industry
Harsh ConditionsRobust measurement solution for industries with heavy-duty operation, rapid flow fluctuations, and a need for reference compressor measurements.
Energy and Infrastructure
Monitoring and BillingCentralized compressed air flow monitoring for energy systems, infrastructure, and facilities where consumption transparency and reliability are critical.
Measuring devices
Tell us what you measure and we will propose the right instrument.
Fill in a short form and we will prepare a proposal for measurement equipment and implementation based on the medium, measuring range, and measurement objective.
Proposal of the right instrument type and measuring range
Measurement reports, trends, and interpretation of results
Supply, installation, calibration, and service
Where to find us
DirectionsPod lipami 4 · 1370 Logatec, Slovenija
Flow Meters
Choose the right flow meter for compressed air, technical gases, steam, or other industrial media. Our portfolio includes thermal, differential pressure, Venturi, and vortex flow meters for a wide range of applications.
VA 526
New deviceNew compact inline flow sensor with Bluetooth, IO-Link and PoE, plus optional pressure and dew point measurement.
Learn more→
CMM 500
Venturi Flow MeterHigh-accuracy Venturi flow meter, ideal for compressor monitoring and compressed air consumption billing.
Learn more→
VA 500
Thermal Flow MeterThermal mass flow meter for compressed air and gases with RS-485, 4–20 mA, and pulse outputs.
Learn more→
VA 520
Inline Thermal Flow MeterThermal flow meter with integrated measuring section for distribution systems and consumption monitoring.
Learn more→
VA 550
Industrial Thermal Flow MeterRobust thermal flow meter for demanding industrial applications, also available with ATEX and DVGW approvals.
Learn more→
VA 570
Flow Consumption MeterThermal flow meter with a compact measuring section, ideal for consumption monitoring and cost allocation.
Learn more→
VA 521
Compact Inline Flow MeterCompact inline flow meter for compressed air and gases, suitable for smaller pipelines and machinery.
Learn more→
VA 525
Compact Inline Flow MeterCompact inline flow meter for compressed air or nitrogen in specialized applications.
Learn more→
VD 500
Differential Pressure Flow MeterDifferential pressure flow meter for wet compressed air or gases with a wide measuring range.
Learn more→
VD 520
Inline Differential Flow MeterInline differential pressure flow meter with an integrated flow conditioner.
Learn more→
VD 550
Heavy-Duty Differential Flow MeterRobust differential pressure flow meter for wet air or gases in demanding industrial environments.
Learn more→
VD 570
Inline Differential Flow MeterInline differential pressure flow meter for larger pipelines and industrial processes.
Learn more→
VU 570
Vortex Ultrasonic Flow MeterVortex ultrasonic flow meter for technical and mixed gases, offering high measurement accuracy.
Learn more→
VX 570
Vortex Flow MeterVortex flow meter for gases, steam, and liquids with integrated pressure and temperature compensation.
Learn more→