Aerzen Rotary Piston Gas Meters

Electronic compact volume converter UNIGAS PTZ CompactThe volume converter UNIGAS PTZ Compact designedespecially for the requirements in gas measuring is optionallyavailable for Aerzen Rotary Piston Gas meters or caneven be retrofitted.Task:The state volume converter UNIGAS PTZ converts themeasured gas volume V bof one gas meter at operationcondition into m 3 dry gas from standard condition p n=1,01325 bar and T n= 273,15 K. The compressibility isconsidered as fixed value or acc. to charts stored in thecomputing device pressure- and temperature dependent.The conversion is effected acc. to the following formula:V n= volume at standard condition (DIN 1343) in m 3p n= standard value of pressure = 1,01325 barT n= standard value of temperature = 273,15 KV b= volume at operation condition in m 3p abs= operation value of gas pressure in barT = operation value of gas temperature in KelvinK = compressibility factorOperating principle:In operation the volume gas meter transmits impulsesproportional to the measured flow to the processor ofthe UNIGAS PTZ by means of a low frequency impulseconverter mounted in or at the gas meter. The processorreceives the values of the operation pressure and -temperaturefrom the sensors, which are either installed directlyat the gas meter or in the piping.Retrievable data:During operation the UNIGAS PTZ indicates the actualvolume at standard condition via the LCD-display. Bydepression of a key, the following values can be retrievedin addition:• operation cubic meter V b• gas temperature in °C• operation pressure p absin bar• condition indicator Z• fault codes• battery consumption in mAh• operating hours• fault register for V n• fault register for V b• compressibility factor K• remote data transfer on requestScope of supply:UNIGAS PTZ consists of the microprocessor controlledcomputing device, the pressure- and the temperaturesensors and an optimised 3-way test cock. The computingdevice can be mounted directly to the gas meter or separatelyand is certified for use in hazardous areas accordingto (EEX ia IIc T4).Pressure rangesP abs= 0,8 bar to 2,8 barP abs= 0,9 bar to 6,0 barP abs= 2,0 bar to 10,0 barTemperature rangesGas temperatures -10 °C to 40 °CAmbient temperatures -25 °C to 55 °CGas typesNatural gas acc. to DVGW-worksheet G 260,technical gasesAccuracyTotal errors of measurement (reproducibility, hysteresis,room temperature) within ± 0,3 % from measured value.Impulse outputA standard m 3 impulse output with pulse times of 10 ms,30 ms, 40 ms or 100 ms is programmable.Furthermore, an actual m 3 impulse output or a fault indicationoutput is also programmable.Data interface RS 232, as well as remote data transfer(protocol IEC 1107 Mode C, VDEW 2.0, Görlitz) are alsoavailable.10