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EVC (Electrical Volume Corrector)

EVC adopts intelligent integrated design which can dynamically test the temperature and pressure of the medium and perform automatic compensation and compression factor correction.

EVC can directly display the standard instantaneous volume flow and the standard total volume of the gas. The product has been proved that their performance is reliable and can be widely used with turbine rotary flow meters and other instruments.


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Electric Volume Corrector for Gas Meters
Electric Volume Corrector for Gas Meters


EVC (Electrical Volume Corrector)

Performance characteristics in overview

  • Ambient temperature: -25℃~+60℃
  • Medium temperature:-30℃~+80℃
  • Relative humidity:5%~95%
  • Atmospheric pressure:70kPa~106kPa
  • Explosion-proof grade: ExiaⅡCT4 Ga; Protection grade: IP65


Power supply and consumption

A. Internal power supply: 3.6V lithium battery power supplythe average power consumption is less than 1mW (two lithium batteries can be used for more than 5 years).

B. External power supply: DC24V ± 10% when the external power is connected the circuit automatically switches to the external power supply and the power consumption is less than 1W.

Input signal

A .Flow signal: (0 ~ 1500) Hz; (Pulse amplitude is 3V)

B. Temperature signal: -35 ℃ ~ + 125 ℃ (PT1000 platinum resistance Accuracy: ≤ ± 0.5%)

C. Pressure signal: 0MPa ~ 4MPa (accuracy: ≤ ± 0.5%)

RS485 communication

A. Use photoelectric isolation RS485 interface (communication rate: 2400 bps 4800bps 9600bps; communication method: half-duplex 8 data bits 1 stop bit no parity check)

B. MODBUS RTU protocol

With calorific value display function

Output signal

A. Mechanical pulse signal: the flow pulse signal is output after amplification and shaping by pre-amplifier.(for flowmeter verification)

B. 4mA ~ 20mA standard current: the current analog quantity can correspond to the corrected flow pressure or temperature(optional).
C.Quantitative pulse signal: 0.1m³ 1m³ or 10m³ corresponds to one pulse which is output by OC gate. (Available for IC card controller)

D. Battery low voltage alarm signal: Normally high level low level when battery is low voltage alarm OC gate output.

E. Low battery power shut-off signal: usually high level low level when working OC gate output.

F. Flow / pressure alarm signal: when the instantaneous flow /pressure is lower or higher than the set value it outputs a low level which is usually a high level.

Electrical protection

A. Double isolation of internal power supply: The DC24V power supply terminal is isolated from the chassis and internal processing circuit and can withstand a shock of DC500V for one minute.

B. DC24V power supply is resistant to ± 500V 10ms strong interference impact. RS485 communication is isolated from the DC24V power supply and the chassis and can withstand a shock of DC500V for one minute.

C. DC3.6V power supply has anti-reverse protection.

D. RS-485 communication port has transient voltage suppression function anti-lightning strike anti-static discharge shock;

E. Using photoelectric isolation two-wire current loop can resist 500V 10ms strong interference impact.