CUSTODY TRANSFER MEASUREMENT IN NATURAL GAS DISTRIBUTION
Technical Data:
| Measured values | Volume a.c., volume flow a.c., gas velocity In addition, for integrated volume correction: volume s.c., volume flow s.c. |
| Measurement principle | Ultrasonic transit time difference measurement |
| Measuring medium | Natural gas (dry, odorized) |
| Measuring ranges Volume flow, a. c., DN 50 (2″),Volume flow, a. c., DN 80 (3″),Volume flow, a. c., DN 100 (4″),Volume flow, a. c., DN 100 (4″) | 1.0 … 160 m³/h/,2.5 … 400 m³/h,4.0 … 650 m³/h,4.0 … 1,000 m³/h |
| Reproducibility | ≤ 0.1 % |
| Accuracy Qmin up to 0.1 Qmax,0.1 Qmax up to Qmax,Qmin up to 0.1 Qmax,0.1 Qmax up to Qmax: | Accuracy class 1, typical error limits:≤ ± 1 %,≤ ± 0.5 %,Accuracy class 1, maximum allowed error limits,≤ ± 2 %,≤ ± 1 % |
| Diagnostics functions: | Permanent monitoring of measured values |
| Gas temperature: | –25 °C … +60 °C,–40 °C … +70 °C |
| Operating pressure: | PN16 (EN 1092-1): 0 bar (g) … 16 bar (g) Class 150 (ASME B16.5): 0 bar (g) … 20 bar (g) |
| Ambient temperature: | –25 °C … +60 °C,–40 °C … +70 °C |
| Storage temperature: | –40 °C … +80 °C |
| Conformities: | OIML R137 1&2, 2012 EN 12405 : 2010 (with integrated volume correction) MID: 2014/32/EU PED: 2014/68/EU ATEX: 2014/34/EU EMC: 2014/30/EU |
| Ex-approvals IECEx,ATEX NEC/CEC (US/CA) |
Ex ia [ia] IIC T4 Gb, Ex op is IIC T4 Gb II 2G Ex ia [ia] IIC T4 Gb, II 2G Ex op is IIC T4 Gb CSA: I.S. for Class 1 Division 1 Groups C & D T4; Ex/AEx ia IIB T4 Ga |
| Conformities: | OIML R137 1&2, 2012 EN 12405 : 2010 (with integrated volume correction) MID: 2014/32/EU PED: 2014/68/EU ATEX: 2014/34/EU EMC: 2014/30/EU |
| Ex-approvals IECEx,ATEX NEC/CEC (US/CA) |
Ex ia [ia] IIC T4 Gb, Ex op is IIC T4 Gb II 2G Ex ia [ia] IIC T4 Gb, II 2G Ex op is IIC T4 Gb CSA: I.S. for Class 1 Division 1 Groups C & D T4; Ex/AEx ia IIB T4 Ga |
| Enclosure rating: | IP 66 |
| Digital outputs | Configurations:
• LF pulses + malfunction, electrically isolated (fmax = 100 Hz) • HF pulses + malfunction, electrically isolated (fmax = 2 kHz) • Encoder + LF pulses, electrically isolated (fmax = 100 Hz) • Encoder, electrically isolated + HF pulses, not electrically isolated (fmax = 2 kHz) • 2 x LF pulses, electrically isolated (fmax = 100 Hz) |
| Interfaces | RS-485 module (externally powered) alternative to digital outputs, Modbus RTU protocol, Optical interface (according to EN62056-21 (Section 4.3) |
| Dimensions (W x H x D) | See dimensional drawings |
| Weight | See dimensional drawings |
| Material in contact with media | Aluminum AC-42100-S-T6 |
| Mounting | Horizontal or vertical installation with 0 D straight inlet/outlet piping |
| Electrical connection Voltage | Intrinsically safe supply: 4.5 … 16 V DC Inclusive 3-months back-up battery |
| Options | Self-sufficient meter configuration (more than 5 years battery runtime) |
Volume correction:
| Accuracy Correction factor C: | Accuracy class 0.5; Maximum allowed error limits:≤ ± 0.5 % (at reference conditions) |
| Correction method | pTZ or TZ |
| Compressibility | SGERG88 AGA 8 Gross method 1 AGA 8 Gross method 2 AGA NX-19 AGA NX-19 mod. GERG91 Fixed value |
| Data archives | Measurement period archive (6,000 entries) Daily archive (600 entries) Monthly archive (25 entries) |
| Log books | • Event log book (1,000 entries)
• Parameter log book (250 entries) • Metrology log book (100 entries) |
Pressure sensor:
| Measuring ranges
Absolute pressure Relative pressure |
0.8 … 5.2 bar (a) / 2 … 10 bar (a) / 4 … 20 bar (a) 0 … 4 bar (g) / 0 … 10 bar (g) / 0 … 20 bar (g) |
Temperature sensor:
| Measuring ranges Temperature | –25 … 60 °C / –40 … 70 °C |
| Sensor type | Platinum resistance sensor Pt1000 in stainless steel protective tube |
| Ambient temperature | -40 °C … +85°C |
