evc adopts intelligent integrated design which can dynamically test the temperature and pressure of the medium and perform automatic compensation and compression factor correction. it 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.
● advanced microcomputer technology and high-performance single-chip microcomputer selected high-quality electronic components make the machine more
powerful and superior performance.
● advanced dual-power micro-power consumption technology low power consumption of the whole machine not only can run for 5 years with internal battery but also can be connected to external power supply for operation.
● advanced dual-power micro-power consumption technology low power consumption of the whole machine not only can run for 5 years with internal battery
but also can be connected to external power supply for operation.
● 4-20ma standard analog signal output can correspond to flowpressure temperature (optional);
●using rs4 85 interface and modb us protocol a remote data collection and monitoring system can be formed through gprs / cdma and internet which is convenient for centralized data collection and real-time management.
● using flash data storage technology parameters can be stored for a long time after power off.
● internal battery low voltage alarm to remind users to replace the battery in time.
● have different interfaces to meet different installation methods.
● independent battery compartment easy for users to install without affecting the use of the motherboard.
● the cover and body of the flow meter are equipped with seals to
● multiple cable output terminals convenient for user signal acquisition and processing measurement calibration and power management.
●when accidental power failure automatically save data to prevent data loss.
● high-quality lcd screen can withstand 80 ℃ high temperature and -25 ℃ low temperature.
● the external power supply is isolated from the main circuit of evcand the isolation voltage is up to 1000v.
● reliable electromagnetic compatibility design.
●support digital signal output and analog signal output pressure sensor to meet different requirements and cost control.
● the temperature and pressure sensors are external and the i 2 c interface is used for data communication with the correction instrument. the measurement accuracy not effected by the correction instrument. the same specifications can be directly interchanged so it is easy to verify and use.
● 60-day hour record and 180-day day record for easy data query.
● the linear segment correction function improves measurement accuracy.
● when the input signal is a quantitative pulse signal a dual-display smart meter can be formed with the mechanical meter with a
counter.
● intrinsically safe circuit design is suitable for use in occasions with explosion-proof requirements.
● infrared remote control operation you can query and modify the instrument parameters without opening the cover (optional).
functions and features:
● conditions of use
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.
features
