Thermal flow sensor VA 525

massairgas

Overview
The VA 525 combines modern digital interfaces for connection to energy monitoring systems with a small, compact design. The VA 525 is intended where many compressed-air consumers (machines) must be integrated into an energy monitoring network. Monitor individual machine consumption and analyse leak flows using a single measuring device to support energy management and sustainability goals.

General information
No inlet run required - integrated flow rectifier - optional pressure sensor. Available with optional analog outputs (4...20 mA, pulse) and digital interfaces (Modbus RTU via RS485, optional M-Bus, Ethernet/PoE). All interfaces are accessible via a freely configurable display.

VA 525 flow measurement ranges (max 185 m/s) for compressed air (ISO 1217:1000 mbar, 20 °C)
measuring section | thread | full scale | m3/h / (cfm) | L | B | H1 | H | A
DN 8 | G 1/4" | 105 l/min | 3.6 (cfm) | 135 | 55 | 50 | 109.1 | 15
DN 15 | G 1/2" | 90 m3/h | 50 | 135 | 55 | 50 | 109.1 | 20
DN 20 | G 3/4" | 170 m3/h | 100 | 135 | 55 | 50 | 109.1 | 20
DN 25 | G 1" | 290 m3/h | 170 | 135 | 55 | 50 | 109.1 | 25
DN 32 | G 1 1/4" | 530 m3/h | 310 | 135 | 80 | 80 | 139.1 | 25
DN 40 | G 1 1/2" | 730 m3/h | 430 | 135 | 80 | 80 | 139.1 | 25
DN 50 | G 2" | 1195 m3/h | 700 | 135 | 80 | 80 | 139.1 | 30

Advantages

• Compact, small footprint – suitable for installation in and downstream of machines at the end user.
• Optional classical analog signals (4...20 mA, pulse) or digital interfaces (Modbus RTU via RS485, optional M-Bus, Ethernet/PoE).
• All interfaces available via a freely configurable display for on-site parameterisation.

Technical specifications

• Units adjustable via keypad/display: m3/h, m3/min, L/min, L/s, ft/min, cfm, m/s, kg/h, kg/min, g/s, lb/min, lb/h.
• Sensor principle: thermal mass flow sensor.
• Measuring medium: air (compressed air) and compatible technical gases, e.g. nitrogen.
• Measurement ranges: see table above (DN8 to DN50); max version up to 185 m/s.
• Accuracy: ±1.5% of full scale ±0.3% of reading. On request: ±1% FS ±0.3% reading or other options.
• Operating temperature: -20...60 °C.
• Operating pressure: up to 16 bar.
• Pressure measurement (optional): 0...16 bar, accuracy 1% or 10…2000 mbar (abs).
• Digital outputs: RS485 (Modbus-RTU); optional M-Bus; optional Ethernet/PoE interface.
• Analog output: 4...20 mA for m3/h or L/min.
• Pulse output: 1 pulse per m3 or per litre, galvanically isolated; pulse value adjustable via display; pulse output can be used as alarm.
• Power supply: 18...36 VDC, 5 W.
• Load (for analog output): < 500 Ω.
• Housing: polycarbonate, protection class IP65.
• Measuring block: aluminium.
• Measuring block connection threads: G 1/4" to G 2" (BSP) or 1/2" to 2" NPT (variant dependent).
• Mounting position: any.
• Weight (indicative): 3.5 kg.
• Product reference: 0695 5250-A2-E1.