A2G-25 WIKA air flow meter

Description

The A2G-25 air flow meter is designed for accurate air flow measurement of gaseous media in ventilation and air conditioning applications.

It can be used to easily determine the air flow by measuring the differential pressure multiplied by a factor K. The K factor, which depends on the fan used or the size and number of measurement probes of the tubes/ducts, can be easily controlled via the A2G-25 menu. Various air flow calculation formulas are already programmed into the device to give accurate results.

The A2G-25 also offers electrical analogue output signals (DC 0 … 10 V or 4 … 20 mA) and digital Modbus® versions, allowing direct connection to various control systems or building automation.

The measured differential pressure is displayed on the LC display and can be transmitted via analogue or digital output signals. This functionality allows you to combine two measurements in one instrument, ensuring efficiency and ease of operation. The LC display and intuitive menu navigation make it quick and easy to use.

The A2G-25 can measure air flow rates up to 200,000 m3/h and differential pressures up to 7,000 Pa, giving it the reliability for a variety of ventilation and air conditioning applications.

 

Who is A2G-25 suitable for?

• For manufacturers and maintainers of radial fans, as it allows the airflow of these fans to be measured.
• For engineers and technical professionals in the field of ventilation, as it allows the measurement of air flow in ventilation pipes and ducts.
• For HVAC companies, as it allows them to accurately measure the airflow in their systems.
• For maintenance and repair technicians, as it allows differential pressures to be measured to check system performance.
• To optimise the performance of ventilation systems by enabling precise measurement and control of airflow, which can contribute to energy efficiency and room comfort.

 

Technical specifications

• Measuring element: piezo measuring cell
• the measuring area:
  • analogue output signal (DC 0 … 10 V/4 … 20 mA)
    • 0 … 1.000 Pa
    • 0 … 2000 Pa
    • 0 … 5000 Pa
    • 0 … 7000 Pa
  • Modbus® version:
    • 0 … 2,500 Pa
    • 0 … 7000 Pa
• accuracy:
  • measuring ranges 0 … 1.000, 0 … 2.000, 0 … 2.500 Pa
    • Pressure < 125 Pa: 1 % ±2 Pa
    • Pressure > 125 Pa: 1 % ±1 Pa
  • measuring ranges 0 … 5000, 0 … 7000 Pa
    • Pressure < 125 Pa: 1.5 % ±2 Pa
    • Pressure > 125 Pa: 1.5 % ±1 Pa
• units (configurable in the menu):
  • air flow
    • m3/h
    • m3/s
    • l/s
    • cfm
  • differential pressure
    • See
    • kPa
    • mbar
    • inWC
    • mmWC
• Process connector:
  • Connecting nozzle (ABS), bottom bracket, for pipes with internal diameter
  • 4 … 6 mm
• UB supply voltage: AC 24 V or DC 24 V ±10 %
• electrical connection:
  • M16 cable gland
  • Cover: PG
  • screw terminals max. 1.5 mm2
• output signal
  • Voltage VOUT: DC 0 … 10 V
  • OUTPUT: DC 0 … 10 V
  • minimum load: 1 kΩ
• flow
  • VOUT: 4 … 20 mA
  • OUTPUT: 4 … 20 mA
  • minimum load: 500 Ω
• current consumption:
  • DC 0 … 10 V: < 1.0 W
  • 4 … 20 mA: < 1.2 W
  • Modbus®: < 1.3 W
• housing:
  • plastic (ABS)
  • Cover: polycarbonate (PC)
• installation: wall-mounted
• zero point setting:
  • automatically
  • manually via a key on the printed circuit board
• the permissible temperature:
  • medium:
    • -20 … +50 °C
    • -5 … +50 °C, with automatic zero point setting
  • Environment: -40 … +70 °C
• ingress protection according to IEC/EN 60529: IP54
• weight: 150 g

MODBUS:

• Protocol: modbus® over serial line
• Transmission mode: RTU
• Interface: RS-485
• Byte format:
  • (11 bits) in RTU mode
  • Encoding system: 8-bit binary
  • Bits per byte:
    • 1 start bit
    • 8 data bits, the lowest bit is sent first
    • 1 bit for parity
    • 1 stop bit
• data rate: configurable
• Modbus® addresses: 1 … 247 addresses selectable in the configuration menu

 

Optional certificates

• measurement report according to EN 837
• test report 2.2 according to EN 10204
• Inspection certificate 3.1 according to EN 10204

 

Video

 

Other designations: A2G25, A2G 25, A2G_25