Total quantity or scope of tender
Gas analyser requirements
2.1 Compositional analysis
USW is looking for a suitable gas analyser (or various analysers) which can measure concentration of three main gases:
- 0-100% CO2
- 0-100% O2
- Ideally 0-2000 ppm N2O, lower ranges also accepted
- Optional: 0-2000 ppm NH3
USW accepts offers of analysers/sensor which can only measure one of the above, as long as they are oxygen compatible. Relative humidity will be kept as low as possible by passing the waste gases through gas driers. Good resistance to high humidity is preferred. Headspace pressure and temperature will be varied between 0-0.5 barg and 5-25°C, respectively.
Cross-sensitivity among the gases listed above must be less than 1-5% of range measured.
2.2 Electrical & signal requirements
The analyser rating must be IP44 or above, preferable IP65 to provide with splash resistance. The analyser can be installed inside the freight container in order to protect from rain and other weather conditions.
Power supply should be 230V AC, however, we can accommodate lower DC voltages if required. The analyser should have at least 3 analog outputs, one for each gas composition, preferable a single cable/line (RSE); the DAQ devices accept voltage signals from -10 to 10V and current signals (4-20mA). Differential (two cables) are also accepted. Supplier must provide clear instructions (manual) on wiring for signal acquisition. Extra outputs for alarms (e.g. high reading) are also favourable.
2.3 Installation and design considerations
Preferred pipe size is 1/8” internal diameter. The piping materials must compatible with high purity O2 gas, i.e. free of oil, lubricants, and natural rubbers. Stainless steel (300 series) is preferred for this application. All O‐rings in contact with oxygen gas should be made of oxygen compatible materials, typically, fluoroelastomer or a similar fluorocarbon elastomer (FKM/Viton).
Refer to appendix B and C for the analyser configuration options. Other configuration options are welcome.
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