Smart ESM - Wash Water Monitor for Ship Exhaust Gas Cleaning Systems

With the IMO’s 2020 global sulphur cap fast approaching, a popular solution to ensure compliance is to install an exhaust gas cleaning system (EGCS). 

For this, wet scrubber systems use wash water to remove the pollutants from the exhaust gas. Therefore the wash water being discharged must be monitored at all times to ensure it is within the limits set by the regulating body. There are IMO regulations for water quality parameters including Polycyclic Aromatic Hydrocarbons (PAHs), pH and turbidity prior to discharge into the ocean. 

Rivertrace is an ISO 9001 Quality-Assured Company and market leader in Oil in Water Quality Monitoring, with over 30 years’ experience and your partner to ensure that the wash water discharged from your exhaust gas cleaning systems is compliant with the global regulations on discharge. 

Our SMART ESM monitor developed by Rivertrace, is suitable for both the inlet and outlet of a wet exhaust gas cleaning system, measuring and recording PAH, Turbidity, Temperature and pH, on open-loop, closed-loop and hybrid scrubber systems.

The SMART ESM is fully compliant with MEPC 259(68) and provides reliable information to ensure compliance with the worldwide SOx limits

Power supply

100 – 240V AC,  47 – 63 Hz single phase


H480mm x W560 x D183



Operating pressure

Max 4.0 bar 

Ambient operating temp

0 - *50 ºC  *Higher Optional

Sample flow

0.1-4 L/min

PAH range

0 - 4500 µg/L

PAH resolution  

1 µg/L

PAH accuracy 

1 %

Turbidity range

0 - 500 FNU

Turbidity resolution  

0.1 up to 100 NTU, 1 thereafter

Turbidity accuracy 

0.1 up to 100 NTU, 1 thereafter

pH range

0 - 14

pH resolution 


pH accuracy 


System outputs

RS485 Modbus 

TCP/IP Ethernet (RJ45) 

4x Volt free relay contacts for each parameter measured

4x 4-20 mA output for each parameter measured

SD Card for storing 

Display/user interface

10.1” capacitive touchscreen

Sample inlet/outlet

¼” BSPP threaded holes

Monitor  configuration

The control module and cell module with individual PAH and turbidity cartridges, are separate units on a backplate to ensure easy calibration and maintenance 



Regulatory Approvals

DNV GL Statement of Compliance (Pending)