UV500 IMO measurement principle
- UV500 IMO is a specific on-line water analyser which provides a simple and fast method to measure PAH (Polycyclic Aromatic Hydrocarbons), pH, turbidity, and temperature using different modules. This analyser is designed to monitor inlet or outlet washwater of exhaust gas cleaning system with good accuracy, stability, and low operating cost. UV500 IMO can also be easily applied for open-loop, closed-loop or hybrid scrubber. The analyser is fully compliant with the MEPC 259(68) discharge criteria.
- An UV-fluorescence module allows the measurement of PAH in terms of equivalent concentration of phenanthrene(PAHpheeq). Infra-red laser diode is used to monitor turbidity by nephelometry. Internal probes allow to monitor pH and temperature.
- Thanks to its automatic cleaning system, the maintenance is roughly limited to a periodic refill of the inexpensive cleaning solution.
- All the measurements are done within 5 seconds.
- The UV source used for PAH measurement is xenon flash lamp specified for 109 flashes that corresponds to more than 10 years of lifetime with one measurements every minute.
- The infrared laser diode employed for turbidity complies with the ISO 7027:1999 standards.
UV fluorescence principle
1 : Xenon lamp,
2 : excitation filter,
3 : flow cell,
4 : emission filter,
5 : photomultiplier,
6 : reference photo detector
Laser diode turbidity principal (nephelometric)
1 : Laser diode (650 nm or 850 nm),
2 : flow cell,
3 : Photo detector
Patented flow cell
1 : The patented flow cell allows to analyse very high level of suspended solids without clogging, making it suitable for industrial and municipal wastewater applications.
- The wetted parts of the flow cell make it also suitable for most corrosive samples. The turbidity is automatically compensated by a dual-wavelength method.
- he design with two cylinders enables the water to go around them, avoiding suspended particles to agglomerate and interfere with the optical measurements.
- Wetted parts of flow cell make it suitable for most corrosive sample
User-friendly interface
The large colour touch screen (10.4”) and intuitive interface available in 9 different languages (Chinese, English, French, German, Hungarian, Italian, Portuguese, Spanish, Turkish) makes very easy to test or configure the analyser.
Many test functions allow to test and troubleshoot each element of the analysers (light single, pump, solenoid valves, etc…) to set up quickly a maintenance diagnostic.
An acid resistant protection film on the screen assumes an efficient long-term protection.
Communication
The RS232 port supports the MODBUS protocol to transmit each measuring channel value to a SCADA system.
Additional parameters are available like status code, error code, calibration values and pumps run time.
Basic 4-20 mA output modules can be plugged on the main board for each measuring channel, in the limit of 12 modules. A USB port enables to download on any USB key the last 5000 recorded measurements as well as a diagnostic file containing the configuration and useful information for remote troubleshooting. The recorded measurements file can be imported to Excel for graphs or other treatments. The software of the analyser can be upgraded by connecting a USB key.
Multiplexing system
When different streams need to be analysed, an optional multiplexing system delivers relay contacts to control external electric-valves or external pumps.
UV500 IMO can control two solenoid valves to select the inlet or the outlet of EGC system.
The 8 parameters (PAH, Turbidity, Temperature, pH) for inlet and outlet water can be displayed at the same time on the screen.
Autocleaning
The analyser is designed to automatically clean itself including the pH probe with an adjustable time range, typically 24 hours, using sulfuric acid 5%. This autocleaning with sulfuric acid 5% proves to be more efficient than water or air autocleaning for dirty and oily samples. It prevents any clogging in the hydraulic circuit from heavily charged water samples. This autocleaning design enables uninterrupted measurements and low maintenance.
Autozeroing
Sulfuric acid has no absorbance in the UV-visible, making it an ideal component to measure the zero. At the end of each autocleaning cycle, the zero is performed on the sulfuric acid 5%. This frequency of zeroing is the key for successful measurements as it prevents any drift in the zero to occur.
Sampling system
The UV500 can adapt to many different kind of sampling depending of the application : surface water, drinking water, process water or wastewater.
If the water is already pressurized, the sample can be admitted directly inside the analyser with a maximal pressure of 4 bars. Otherwise an optional built-in peristaltic pump, synchronised with the measurement to extend the tubing life time, allows to take the sample directly from a tank located up to 6 meters below the analyser. For demanding applications with long distances, another peristaltic pump in a separate enclosure is proposed as an option. For some applications on river water or wastewater where two sampling pumps are necessary, the UV500 delivers a relay contact to synchronise the primary pump. The delay and running time of each pump can be adjusted easily in the parameters menu of the analyser.
Internal view of the analyser
