Calorimeter
CWD SPC
The CWD SPC (System Purge Certified) is a combustion calorimeter specifically designed for outdoor installation and continuous determination of gas quality in potentially explosive atmospheres. As part of the CWD series – Calorimetry, Wobbe Index and Specific Gravity – it provides reliable measurement of key gas quality parameters, including calorific and heating value, Wobbe index, specific density, and CARI (air requirement).
The CWD SPC is designed for use in hazardous environments classified as Class I, Division 2, Groups B, C and D, Temperature Class T4. Its system-purge concept enables safe and reliable operation under demanding outdoor conditions and complies with relevant requirements including NFPA 496 (2013) and ANSI/ISA 1212.01.
Typical areas of application include flare gas combustion, gas turbine control, and fuel control in refineries and petrochemical plants. The combination of continuous gas quality measurement, outdoor capability, and suitability for potentially explosive atmospheres makes the CWD SPC a robust solution for industrial applications requiring reliable process monitoring and control under challenging environmental conditions.
| Parameter | Value |
|---|---|
| Weight | Up to approx. 250 kg |
| Dimensions (H × W × D) | 1150 × 2000 × 600 mm |
| Protection Rating | IP64 (NEMA 4X) |
| Ex Classification | Class I, Div. 2, Group B, C, D, T4 |
| Ambient Temperature | −20 °C to +45 °C |
| Ambient Humidity | 0–95% Relative Humidity |
| Ambient Pressure | 800–1100 hPa (0.8–1.1 bar) |
| Gas Inlet Pressure | 30–40 mbar |
| Process Gas Inlet | 1, additional optional |
| Test Gas Inlet | 1 per measuring range |
| Carrier Gas Inlet | Max. 1 |
| Relative Gas Humidity | ≤ 95%, non-condensing |
| Gas Inlet Temperature | Max. 45 °C |
| Instrument Air Consumption | 30 m³/h (standard conditions) |
| Instrument Air Pressure | Min. 5 bar, Max. 10 bar |
| Supply Voltage | 240 VAC, 50/60 Hz; 110 VAC, 60 Hz |
| Interfaces | 8× SPDT Relays, 3× 4–20 mA, additional optional, optional bus systems |
| T90 Response Time | < 15 s |
| Certifications / Compliance | NFPA 496: 2013; ANSI/ISA 12.12.01 |
| Junction Box Approval | IECEx PTB 09.0048; PTB ATEX 1108 |
The CWD product series in comparison
CWD BASIC
Reliable measurement of calorific
and heating value as well as Wobbe index
CWD PLUS
Continuous, highly accurate determination of the Wobbe index
CWD DPC
for use in accordance with Class I Division 2, Groups B, C, D, T4
CWD SPC
Reliable, reproducible measured values in real time for optimum monitoring
CWD EXP
Safe shutdown with changing gas composition Gas composition
CWD HT
The new CWD for precise measured values in the high temperature range
Industry applications
These products can be used in the following sectors.
Iron and steel production
Our appliance series have been used in iron and steel production for many decades.
Biogas
Union Instruments products have proven themselves extensively in biogas upgrading plants.
Petrochemicals and refineries
We produce customized and flexible measurement technology solutions for the petrochemical industry and refineries.
Glass and ceramics
Perfectly coordinated appliance technology for glass and ceramic applications that works both safely and economically.
Natural gas
Our INCA multi-gas analyzers provide efficient solutions for processes in natural gas plants.
Generating energy from waste
Our appliance technology makes an important contribution to the functionality of environmentally friendly and energy-saving system concepts.
Service
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+49 721 680381-30
Support
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Distribution
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Industries
Our key application areas at a glance.
We supply a wide range of industrial plants such as steel production, the natural gas industry and biogas producers.
Products
Special products for your industrial application.
Our range includes the INCA, CWD and SIRA product series and the CAM module – combined with top advice and service.