How to Clean Deckma OMD 24 Measuring Cell

Francis Wong
Francis Wong
Managing Director
Creating no-code websites and informative articles, such as this one, is what I enjoy. I also have a passion for search marketing and SEO.

The Deckma OMD 24 is a 15 ppm bilge alarm that monitors the oil content in the water discharged from ships. It uses a measuring cell that consists of a sample glass tube, a light source and a photodetector. The measuring cell needs to be cleaned regularly to ensure accurate readings and prevent damage. The default oil content monitor for all oily water separators from RWO GmbH is the OMD by Deckma. This article lists the part numbers for RWO's products including for the OMD.

Here are the steps to clean the measuring cell manually or mechanically, depending on the level of contamination. The recommendations follow a progressive order of intensity.

Manual Cleaning

- Stop any water flow to the OMD 24.

- Unscrew the cell cap, MCU or auto-clean (*not all united are equipped with MCU or auto-clean) from the measuring cell and remove it.

- Use the cell cleaning brush (part number: TOIESP313523) from the service kit OMD 24/2008 (part number: SPSVIE318306) to clean the sample glass tube. Wet the brush and move it up and down through the tube several times.

- Screw back the cell cap, MCU or autoclean and make sure it is tight.

- Switch the clean water valve to fresh water and let it flow through the instrument for a few minutes.

4 steps approach for manual cleaning

Mechanical Cleaning

- If the manual cleaning is not enough, you can use a powered screwdriver to assist with the cleaning process.

- Cut the upper part of the cell cleaning brush and insert the wire stem into a screwdriver. Fix it securely.

- Use the screwdriver to rotate the cell cleaning brush slowly in the sample glass tube for a few minutes. Flush with clean water and re-test.

- If there is still contamination, you can use a sample tube cleaner from the service kit. Apply it to the cell cleaning brush and add water. Repeat the cleaning process with the screwdriver.

Cleaning with sample tube cleaner
Cleaning mechanically assisted

Cleaning of Iron Oxide and Calcification

- If there is iron oxide or calcification in the measuring cell, you can use the special cleaning agent available in the service kit OMD 24/2008. In case that is unavailable, you may use citric acid or vinegar.

- Mix the cleaning agent with water in a ratio of 1:10 and fill it into a container.

- Disconnect the sample inlet hose from the OMD 24 and connect it to the container with the cleaning solution.

- Switch on the instrument and let it run for about 15 minutes. The solution will dissolve the iron oxide or calcification in the measuring cell.

- Switch off the instrument and reconnect the sample inlet hose to the OMD 24.

- Flush with clean water for at least 10 minutes.

Cleaning of Iron Oxide and Calcification

The manufacturer advises keeping the service kit OMD 24/2008 on the vessel. It can help fix errors in the measuring cell readings that may occur due to sample tube contamination. Inside this kit, it consist of: 

  • 1 pc protective carrying case
  • 3 pcs of cell brush
  • 1 pc of desiccator cartridge (IEGUGU351636)
  • 3 set o-ring OMD 24/2008 (SEKIED317244)
  • 1 pc Citric Acid 50ml
  • 1 pc Sample cleaner 75ml

We hope this article has answered your questions about the design change of the OWS adsorber cartridges. If you have any further inquiries, please feel free to contact us. We are always happy to assist you with your oily water separator needs.

N&P Maritime is an authorized Singapore based service partner for RWO GmbH since 2016. We are one of their 40 global service stations. Our services include: 

  1. Troubleshoot/Repair,
  2. Authorized Deckma OCM(OMD) calibration
  3. RWO equipment health check

N&P Maritime has an extensive inventory for RWO/Deckma consumable spare parts such as coalescer filter, absorber polisher, zinc anodes, gauges, desiccators and more, in our warehouse.

We are able to provide same day delivery and there is no minimum order requirement.

Contact us at and/or +65 97684033 if you have any questions.

*RWO GmbH has been supplying future-proof made in Germany solutions for marine water treatment for over 45 years. Their product portfolio includes equipment for the treatment of drinking and process water as well as systems for pollution prevention such as oily water separators or sewage treatment plants. RWO is a technological leader in the field of oil/water-separation with over 16,000 units delivered worldwide. More than 40 global sales and service stations.


[Deckma OMD Series Servicing And Cleaning Manual]

[Deckma OMD 24 Series Instruction Manual]